Just spotted this. Nice, pop me down for one.
Also if you need any help on game logo bitmaps for the LCD, for variants to distinguish between regions and stuff, just ask
Just a small update for now. I have one prototype built which seems to be working (which probably makes it not a prototype now):
Here's the underside, you can see both locations for the headers to cater for both versions of the S16 multi:
My S16 multi is misbehaving slightly in that I think one EPROM is slightly iffy so I'd like to get to the bottom of that first before I progress much further with the selector firmware.