Different razors can and often do shave very differently, even when using the same blade in each. It could be the razor + blade combination that is giving you trouble with the Gillette Super Adjustable. If the Super Adjustable gives you trouble with all blades, then maybe it is just the razor geometry, weight, etc. that does not work well for you. Determining if it is the nickel plating should be easy. Shave with the Merkur 39C or Muhle R89, and then lightly rub a nickel on your freshly shaved face. If you break out in spots, then you are probably allergic to nickel. If you do not suffer any adverse affects, then it is something other than a nickel allergy that gives you problems with the Super Adjustable.
I noticed I get more skin reactions when I shave with my FB, opposed to my RazoRock 3pc. Do you think it has something to do with vintage razors vs. modern razors?
I was thinking once all the red bumps are gone, I'd just hold a nickel plated razor in one place on my neck and see if I get a reaction in that area only. I suppose it could be something else but I tried to keep everything else the same. Same blade, soap, brush, and after shave.
Try a complete shave, all your passes complete with lather, without a blade. I think that would simulate what's going on better than just holding the razor on one spot.
Welcome to my world. Whenever I shave with a nickel plated or chrome plated razor, I get bumps on my neck and cheeks. When I switch to a SS or gold plated razor, I have no problem.
This conversation also ties to this thread as well. theshaveden.com/forums/threads/help-me-out.33774/