I figured the best way to compare the shave of the Cooper Monobilt was to put it against a peer it would have been competing against for sales so I used a 34 - 35 open comb TTO Gillette Aristocrat. So after 3 shaves the verdict is in. The Cooper outperforms the 34 - 35 Aristocrat. The shaves were closer for 5 pass shaves and longer return growth time for all 3 shaves with a blade at different levels of sharpness. The Monobilt has lots of blade exposure but shaves more like a mild razor then aggressive as long as you pay attention to what you are doing. The 34 - 35 Aristocrat is a lot more milder than a Monobilt on all accounts. With that said it is one of the closest non-adjustable TTO Gillette shavers you can get. There are only 2 I've used that shave closer, more on that below. I'd like to give points to the Aristocrat for less burn after the shave but a vinegar splash neutralizes that advantage that a milder razor should have. Does the Cooper beat the whole Gillette TTO lineup the answer is no. The Gillette Diplomat holds it own against a Cooper even though it can be a face ripper at times where as the Monobilt isn't. Even though the Cooper has more blade exposure aggression wise they are pretty evenly matched up. It is too close for me to call it. The 47 - 50 NDC notched Aristocrat is the one razor the Cooper loses to. It may shave smoother but not closer than this Aristocrat. With that said the Cooper is a keeper and from a preference standpoint I like the Cooper better since I can shave it faster with less irritation, nicks and cuts than the 47 - 50 NDC Aristocrat.
I am going to add to this in a few days once I get some shaves in with 37 - 39 Sheraton and 38 - 39 Senator. I know about where the Senator will fall in comparison but I've yet to use the Sheraton. The reason for these 2 is they both have different shave heads than the 34 - 35 Aristocrat and therefore would be a good representative cross section of the types of shaves a Monobilt was competing against for customers.
I am not quite there yet for the Cooper. It is a solid over-engineered razor. Everything about this razor screams modern not a 30s razor right down to the chrome finish. The only cooler looking and over-engineered razor than a Cooper I think is a Gillette toggle. Interestingly enough outside of those cheap plastic flip top razors no one has made a modern version of a Monobilt just like the Toggle. The only reason I am not there as this being a be all end all razor is in the rushed for time shave, this is not the razor I would pick up. I don't think I can shave this one fast without paying much attention. Maybe that will change as I become more familiar with this razor.
My favorite to shave with as well. There's a few razors that give as good a shave. 1936 Brit Aristocrat and the No. 58. The only American razor that even comes close is the Blackbird, and (sorry, Shane) the Cooper is much easier to use. Riding the cap on the Cooper takes away it's teeth. (Pun intended). It does turn it into a very mild razor, though. Edit: I'd like to see an adjustable version of the Monobilt someday. That would be a great razor.
The results are in for the 37 - 39 Sheraton and surprisingly this one is in the same ballpark as the Monobilt. The equivalent Gillette shaver would be a Diplomat. They shave almost the same right down to deceptive lack of aggressiveness. If the 36 and up open comb TTO US Aristocrats with the higher profile heads follow suite then they should shave the same. They lose points for irritation during the shave unlike a Monobilt or 34 -35 Aristocrat.
For anyone following who wants a visual of the different head styles of the 3 razors Cooper would have been competing against back in the day. Left to right Low profile head, riveted endcaps, 34 - 35 Aristocrat (pictured), 37 Sheraton High profile head, riveted endcaps 37 - 39 Sheraton (pictured), 36 - 39 Aristocrat, 38 Senator High profile head, non riveted end caps, 38 - 39 Senator (pictured), 39 Aristocrat, 39 Sheraton There may also be a difference between blade exposure and aggressiveness of different razors with the same types of heads for this time period. Cooper for the Monobilt on the other hand made 2 separate handle styles but the head types and shave were the same.
Links for the pertinent patients Gillette patent https://patents.google.com/patent/US1856329A/en?oq=1856329 Cooper patents https://patents.google.com/patent/US1879900?oq=1879900 https://patents.google.com/patent/US1980202?oq=1980202 Looking at the patents the only thing the Monobilt nicked from that patent is those rounded end cap bars. Unless Gillette could have made a case of unique functionality for a hinge there is no infringement. Either way it is fascinating that Gillette was looking at the same idea 4 years earlier. Also if nothing else this puts the Coopers with the 1980202 patent info on the under side as 1934 or later.
The other smart thing Cooper did is to use the folded tab making the razor compatible to blade design in the Gillette patent without violating it. Can't claim unique functionality if it isn't used specifically as a new way to hold existing blades in place. If Gillette did take them court over that they and lost removing the tab wouldn't affect the functionality one bit. Everything I can see says the Monobilt was a well thought out and deliberate design on many levels.
Just an aside, but note the patent was filed before Gaisman took over Gillette and was assigned to the company on issue.
The final results are in for the 38-39 Senator. I always knew this was a good razor but not just how good a razor it is. This razor outperformed all the razors for closeness of shave. This one might even be better than the 47 -50 notched NDC Aristocrat. So to summarize, a/b means can go either way closest shave in order of razors 38 - 39 Senator, Monobilt / 37 - 39 Sheraton, 34 -35 Aristocrat mildest shaver 34 -35 Aristocrat, Monobilt, 38 -39 Senator, 37 - 39 Sheraton Keep in mind these are not mild razors. With that said though they all sit towards the low end of the aggressive scale except for the Sheraton. The only thing I see with keeping the Cooper from being an aggressive shaver is it is easy to tame angle wise. The amount of blade exposure is what makes it an inherently an aggressive razor. ease of shave 34 - 35 Aristocrat, 38 -39 Senator, Monobilt, 37 - 39 Sheraton The aristocrat shaves like butter, it has that optimal balance of blade exposure and feel that makes it makes it easy to work with regardless of most angles and pressure. The results are consistent and since it doesn't have much bite though it will nick you if you don't pay it the proper respect, you can just shave and not concern yourself to much with other shave factors. The monobilt though mild you really need to pay attention to what you are doing. The Senator once you work out the angle it is smooth sailing as long as you don't deviate much from it or when all else fails ride the cap. You'll get great results either way. The Sheraton on the other hand is a real face ripper regardless of angle and not a pleasant experience to shave with but if you like aggressive this one is the most aggressive of the bunch. If you prefer close as possible a Senator it is, if it speed then the Aristocrat, if you want a balanced approach then Monobilt it is. Even though I have it rated lower on ease of shave there is also a lack of familiarity aspect to the razor which over time I expect will not be as much of an issue on the ease part. With that said it is not an intuitive razor to use unlike the others.
I should end with some shopping tips for anyone who is using this as a guide and is looking to buy to use as a shaver. Monobilts just pay attention to base plates and check to see if they are bent or not. If you can fix razors this shouldn't be an issue. Also expect to find prices all over the map for this razor, price it based on what you would be willing to pay for one since there isn't any market driven prices. They don't come up for sale that often. You'll know when they are priced too high if you see them on certain websites and they don't sell for months on end. Even if you were willing to pay that price, don't and haggle with the seller first. Worse they can do is say no and even then they won't say no to your cash at the original asking price afterwards if you still want it. Shop the Gillettes based on the head profiles if you like a certain type of razor but be advised any open comb Aristocrats you are going to pay a premium for when they do show up for sale online. Which is not that often but when one does show up and sells usually a bunch more show up right away trying to ride the sales momentum.
Strange that the Sheraton and Senator get such wildly differing results for you. Aside from the type of screw in the handle, mine look and shave almost identically. As for what razor design specifically inspired the Cooper MonoBilt, I would have to say that it is the Bigelow & Parkin razor, patented in 1921.
If your Senator and Sheraton both had the riveted lifter end caps or non-riveted end caps then that is why they should shave the same. Same heads, same shave.
I shaved with my Monobilt today. Ultimately a fine shave but jeez is it mild. Take a look at this head with the cap fully tightened as I shaved today : ZERO gap and negative exposure. Second photo is with it backed off about a quarter turn. Gap and neutral exposure. That's a pretty significant difference.