It's a shame you couldn't get it to work Primo, maybe OS went through reformulations like Williams did. I'm not sure. My only experience with the soap was a small scrap at the bottom of a OS mug I picked up. There was only enough for one test lather but it worked up to a beautiful thick stable yogurt consistency.
a lot of what gets put in old spice mugs on ebay for example isn't always old spice shave soap. Once almost bought a NOS old spice soap and mug... but thought 45$ was a tad steep when I saw the picture of the soap puck had "colgate" on the top.
From a thread I saw on Badger & Blade, not a member there, some seem to think the closest soap for an Old Spice soap is Mama Bear's "Aged Spice". I really don't know, but hey, it's something to check out if people are looking for it. Another candidate could be Stirling Spice shave soap.
Perhaps covering the puck when curing didn't allow to dry properly? Maybe in a week or so, try it again and see how it works. Excellent project Joseph. Thanks for share you work.
Try shopping around online for a fragrance oil supplier that offers a "dupe" of the fragrance oil you want. Although I don't know the ingredients in the OS Aftershave, I would also venture to say, that by adding equal weight of the aftershave, you diluted the soap's lathering properties significantly with ingredients that shouldn't be in shaving soap. Covering rather than allowing to "cure" open air probably didn't help your cause We mad scientists only learn from our mistakes though, don't we? I've had some rather "interesting" (aka, on the floor comical) results when in full R & D mode! Fun read Paul!