I was also surprised by the closing of Palm Radio, and i wished to have bought another key.
However, because of that, I am working on this:
The design is not finished, there are few things to work out, like sourcing the spring, testing multiple pcb for the spring board (right now using 1/32" pcb), and the detente that allows the locking in the case.
The design was made in Fusion360 - not really open source from that point of view, but I would welcome any design suggestions.
I’m not trying to steal anyone’s design, and would not have published this if Palm Radio was still operating. This work MUST not be used for commercial gain.
JC/W6IPA.