C128 key plungers

[C128 key plungers]

Many Amiga keyboards use the same plungers as the C128, so if you can find plungers out of one of them there's a decent chance it could work.

[Why C128 did stay longer than 1989?]

Commodore dropping the C128 before dropping the C64 weirdly mirrors Apple dropping the IIGS a year before it stopped selling the IIe. They were just selling to schools too well, so well that they wound up selling a card for LC Macs that would run Apple II software as a replacement.