Wow small world, i picked up that same unit at a flea market last weekend. I started to part it out but told myself to wait. Mine is not in good condition.
A goldmine in tubes. Especially the seeing eye tubes are about $35 a piece. I havn't even checked the year yet. but It does seem to be well built! I removed the transformers, one to use on another project but I'm going to wait and just put this thing in the attic for now!