Part sourcing on vintage radios is an art itself. I think it's still easier to do all the work you've done already than deal with restoration.
Crazy to think how much functionality is built into these small sbcs these days. There seems to be a part someone has made that will be of use in any project. The only limitation is your imagination and I see you've got it all setup on a breadboard and working. The real tough part is limiting your project scope or maybe never. The tinkering is hard to stop with so many ideas and I see you have plenty 🙂
Fascinating read and good luck.