Hey-Hey!!!,
But a HV transmitting valve like an RCA 834 would stand the B+ from the anode taps in the power stage. You'd want a triode there anyway. I have been considering just such an arrangement( great minds do reach similar conclusions ). I don't quite like the idea of finding enough 834's. There are a few Hytron valves which are acceptable. They HY51B is similar to 4 parallel sections of a 6SN7 with a plate rating of ~50W and a thoriated tuntsten cathode. I'll bet they look pretty sweet. Probably 866-sized...and these make 834's look common.
It is quite funny, when I started this journey, I was quite of the opinion that current production was the way to go. How things change.
regards,
Douglas