Just wanted to comment on the LISY project that I've recently completed. I bought some LISY80 boards from JLCPCB (5 of them for $30 shipped), bought enough components to build 3 boards from Digikey (about $110 total, did NOT include the Pis). Built up my first board (soldering was pretty simple) and fired it up with a Pi that I had laying around.
It didn't work right away. Turned out the version of LISY I had downloaded didn't work well with my version of full-sized Pi, but I contacted bontango via PM, and he walked me through it. Ralf was VERY helpful and patient. I now have two LISY boards running, one in my TX Sector and one in my Black Hole. It's a great project!
I will likely look into a Bally board for a backup. Once Ralf recommended the JLCPCB option instead of Aisler.net, the price came WAY down and made it a bit of a no-brainer for me. If you've got a board that's not working and don't mind a little tinkering, I fully recommend the LISY project to keep your older games going!
Jeff