[Arran]

That looks a lot like an aircraft connector of some kind, even if it's a U.S.N power supply. I have a book somewhere about War Surplus radios, but I think most of them are U.S Army or aircraft receivers. I think I found what you may be looking for on this site: https://www.navy-radio.com/rcvrs/rbb-rbc.htm At least they have a circuit diagram for the power supply. Also the RBM-5 https://www.navy-radio.com/rcvrs/rbm.htm I think it may be easier to hold off and see if someone wants to swap your supply for a proper, matching one.
Regards
Arran