Thanks for the feedback. I'll have SLA's made of both types of MKIIa knobs so we can see how they look.

Rob, I was considering sourcing those springs but I had no idea where to even start finding them. Do you think they will be expensive... and even worth it?

Oliver, hopefully with my hard plastic polycarbonate buttons, heat (and cold) won't make them soft (or brittle). They should be pretty darn tough, apparently. I plan to stress test the pre-production run when I get them.