Based on my impression that the T3F was a fancy version of the Rabco SL8E, I would have assumed there is not much circuitry involved. Isn't it just a tiny motor that drives the pivot end of the arm wand in response to the opening and closing of a tiny switch due to physical contacts that open and close as the wand describes tiny arcs across the LP surface? (Apologies for abusing the adjective "tiny".) I guess there is more going on that cues the arm wand electronically, at the beginning or end of play. If all else fails, an SL8E schematic or operational diagram would help a lot. Does Goldmund still have representation wherever you are?