I am working on a compact KSR (UGC-20) its all coming together (I picked up a UGC-77 which is a low level type and traded Nick for a UGC-20 base so I could have a 60ma setup) There are a few differences on the low level 77 model the transformer for the lighting is mounted on the typing unit and the plug is wired differently (Bad design because the low level unit has the loop on pins 2 and 3 and the high level has 115vac on the same pins. This would only be a problem when putting a high level typing unit on a low level base.
I picked up my unit from a gentleman that was giving a bunch of teletype stuff away in Northern California. The only issue I am having is the code bars on my typing unit are a bit sticky and sometimes get stuck causing garbage to print. I will get that ironed out over the next couple of weeks. Pretty soon I will have a nice compact KSR that I will have in the guest bedroom (The wife doesn’t know this yet so shhhh)