[Arran]

It looks very much to be along the same lines as one of the Motorola VT-71 style sets, though Emerson probably put their own spin on it, like only using a single selenium rectifier rather then two. The 6 KV caps in the vertical circuit will all have to go before it will do much. I think Bob Andersen may have one of these but hasn't done a restoration on it yet, he is working on one of the earlier ones with the five 25Z6 tubes and a transformer. These basically use a scope tube with a white phosphor rather then a green one, I think the largest electrostatic sets use an 8 or 9'' tube, I've heard of 10'' ones but have never seen an example, not even in a book, after a certain point the resolution hits a limit I think.  
Regards
Arran