Ok finally got all the parts for this and got an hour on it after work carnage. The LM723 was replaced, power supply connector replaced (both ends), power switch replaced, reworked the board, replaced three of the bridge rectifiers as a precaution.
So first the rework... epoxy and copper bus wire
New Molex connectors and bridge rectifiers:
Nwe Molex connectors on the transformer:
After this the thing was powered up and the rails were all good.
So I plugged the interface board back on and the rails bombed pretty quickly which is not good. Visual inspection performed next and I found this bastard hiding which looks suspiciously like a possible culprit for this whole situation...