Work in progress! (This photo didn’t attach to the previous post for some reason). I’d had the thing open years ago to service the belt or something but the old brittle wires gave way and it took some effort to deduce what goes where! It languished in the garage for ages; being raided for parts a couple of times, but I decided to give it another go last night. I couldn’t find a schematic for the whole unit, but the data sheet for the LA4160 amplifier IC was very helpful.