Oh, that can be frustrating when that happens!- whilst it's pleasing to have something working again, it's always good to be able to say, "It was x that needed changing/reflowing/whatever". I'm not familiar with this set, but I'm sure I recall something about Racal biting the bullet and going for swing-out but hard-wired boards. From what I recall of working with edge-type connectors of that sort of era, it might have been wise!
With the complex but hemmed-in replacement transformer requirements, perhaps an outboard PSU with a number of easier small transformers and an umbilical will keep the original going, HRO-style?
