morganfam7, I'm new to this particular process, but I have used a lot of different materials and I know that you can go from thick grunge to silvered decals quicker than you could ever imagine.
Those ones by the take up lever and on the reverse were awful - absolutely buried in hard brown gunk. It just kept coming off a tiny little bit at a time on my q-tips and then all of a sudden, one of the tiny feathered ovals was smeared!
On this second one, I'm going a lot slower even than I did the first time, to allow any possible clear coat to harden up between cleanings. Gonna be a pain in the neck, but this one is potentially even prettier than the first one, although I suspect the clear coat is even more fragile than the first. I may step it down even further and use only sewing machine oil to clean these.
I have three machines and two cabinets in the works. That keeps me from getting too aggressive with any single project. I hope.
Good luck to you and just keep pluggin.