Doh! I have to admit I was a bit suspicous of the whole "no power tubes included" clause - it's part of why I set my max price where I did.
Man, I wish you the best of luck... it should be like any basic power amp though, check the supply voltages, look for burned components, cracked PCB's, and check the output transformer for shorts/opens. If these parts work then it's on to the switching electronics - where, as you indicate, you will probably need a schemtic.
From the looks of the insides of my RM4, it seems that Randall is using opto-switches of some kind, compared to relays used by Egnater. You might try looking at the control voltages for these - if they are in the RT2.