I've gotten ahold of a classic MIDI Fighter board (#1401 if anyone is counting) and I'm going to put it into a bigger enclosure and expand it. My plan is to build a setup like the old MIDI Fighter Pro with 2 knobs, 2 faders, and 4 buttons for bank selecting.

This brings up a question for me, though. I've seen some pictures of the guts of the MIDI Fighter Pro, and it looks like the expanded stuff was all on a daughter board. And if I'm not mistaken, it looks like those sexy square bank select buttons were illuminated-upon-press and had a lockout so only the most-recently-pressed button would be illuminated.

Can this kind of functionality only happen if you have one of those daughter boards, or is there anyone here that can give someone with limited electronics knowledge guidance on how to build that kind of illuminated, lock-out, bank-select button function?