While I was able to get plungers for my Amiga 500 keyboard to replace the broken plunger on my left Amiga key, it seems hard to find replacement keycaps, oh well I only checked on ebay.
So I designed a 3d printable Amiga keycap. It's available here on thingiverse:
https://www.thingiverse.com/thing:6658110While it is not perfect (I think the top surface needs to be shifted slightly forward), it fits well in the plunger, and works good enough as a keycap.
