Well, as I've mentioned in another thread I buggered up the original supply. Even if I fixed the original problem the rest of the PCB has not benefited from my fiddling - it's just become a bore now so I think I'll just try to replace it.
I'm referring to the Moog version, PCB power supply assembly (33441 PN 50887) - it's the type in all Polymoog keyboards and a fair number of the synthesizer units. Heat sink is not necessary.
So if anyone has a spare rattling around somewhere do send me a PM.