[Arran]

If you have the tuner chassis and cabinet those are two of the most important and harder to find parts. Many of these types of sets, Scotts at least, were sold as bare chassis without a cabinet so there are considerably fewer cabinets then there are chassis to go in them, it's likely a similar story with a McMurdo Silver set. The main issue with this set is the 18 inch speaker which had a concentric mount for the tweeter, I don't know if all McMurdo Masterpiece sets used these or not. It may take some time but I think you could probably find a power supply/amplifier chassis eventually. If push came to shove you could always make one from new parts.
Regards
Arran