A friend printed one of these for me, for the original 7800 (since mine had one of the pins missing), but the way it's printed makes the pins vulnerable to breaking off. So it did not last long. 😞
So I figured some things out with help of some skilled Furnace users and I added a bassline (and a snare drum) to a few patterns. Only about 9 orders are currently updated, the rest will be wrong.
Spanish_Flea_updated.fur
Spanish_Flea.mp3
Unfortunately I'm not familiar with Furnace as I only use RMT for my POKEY tunes. I tried fiddling a bit with the instrument editor and could not figure out how to set an instrument up it in a way I needed.
Best I can do is send you some examples of what can be done with just two channels in RMT for inspiration.