Not only did the replacement stomplfo chips show up today, but also a PICkit3 with which to make as many as might be needed. I have raw PIC16F18313 chips here, too.
Well, Looks like I need to poke another hole in the enclosure and box it up.
For those playing at home, offset control all the way down, depth all the way up. I have those as trimpots.
Further for those playing along at home, send the output of the lfo board into pin 7 of the original lfo opamp footprint. I was going to use the board's pot mount but changed ny mind.
This requires wiring the expression jack directly to the rate pot.