I tried dyeing a Model M. The keys, and the stems from the few two piece ones, came out perfectly, but the case just wouldn't take the dye. It would just become a darker gray, looking as if it were just a filthy keyboard.
There was no problem with the dye; I tried enough orders and variations with multiple dye baths and keyboard sets that I can rule out anything like that.
What is the difference between them, and has anyone successfully dyed the case of a Model M?
I suppose that I could just paint and seal the case; since it doesn't get touched often it should last for a long time.