I actually made some 'long' fingerboards years ago on the edge of something else, but I have no idea what happened to them... they were just fingers w/ no holes or anything...
It could be worth your time to lay out and offer a fingerboard "strip" of some multiple of contacts. You could cut off the length/number of contacts you needed. The fingers would have to be long enough to solder wires to them without the solder wicking into the finger being inserted into the edge connector or plug into an edge card connector with enough sticking out to plug into another edge connector. You could also cut the PCB finger traces in the middle with a moto tool and make adapters with them as well. That would be a very handy universal fingerboard. I've cut down down larger jamma fingerboards to match the 22/44 edge connector with no problems in the past. I've been searching with no luck so far for a Gottlieb solution.