Dynamo replaced and all working again

Refitting was no problem, the dimensions are ever so slightly different so the pulley is pushed forward a touch. So will have to watch for fan belt wear.

Or the next knock on effect of replacing the fan belt which will be the water pump bearing giving up the ghost??!!

Re-wiring turned out to be exactly as described in the various documents and internet articles that I had found. Only issue was that by using the "D" terminal it made the ignition light stay on as described in an addendum at the bottom of this article on the subject. (I have found a few useful tips on the MGAGuru site - thanks from an Austineer!)

But nevertheless, not wanting to follow the advice on that page, I just used the redundant earth terminal as my connector instead. So the regulator is now just a glorified connector block: