Are you using catalysed stuff?
I'm using high quality (not cheap!) solvent based auto paint, no catalyst. When it's properly dry its very tough, even wet sanding it, it takes ages to cut back. Adhesion on the primer base is really good. That's why I'm unconcerned about wear and tear on the painted button. With some effort you could scratch it with a sharp metal implement but otherwise it should endure normal finger presses for quite some time. In comparison if you directly painted say, acrylic house paint or poster paint onto these shiny buttons, with no prep, you could easily scratch that off with just a finger nail, I'd expect it to just peel off as well. That's quite a different matter altogether.
I think the real trick is in the surface preparation
This is correct, as I said previously all surfaces get the same sanding prep and primer treatment, all in all, surface prep + auto paint + moderate spray painting skill = the results you see. I learned this process from a skilled auto spray painter.
Quite a few pics coming up to mark the end of this build phase. I'm setting aside the PAC mechanism for now to focus on the cabinet build again.
The last few little parts for the PAC plate fabricated and painted.
These parts screwed in place to the PAC plate.
The rear of the PAC plate showing the modified Happ button in use in the PAC eject mechanism.
The PAC plate screwed into place in the steel side panel insert.
This is what was in my head...now made real!
Imagine how many words it would take to describe that, no one would understand a rambling description of that anyhow
PAC prototype in place. I've got my quote to get 16 of these laser CNC cut (including blue acrylic eyes) which I'll get done towards the end of the build.
Time for a well earned beer