Miller 6183 horizontal blocking oscillator

[PaulOF]

Hi,
I'm looking at plans for a 1960 vintage double conversion superhet that I have almost all the stuff I would need to build in my scrap box. I was thinking it might be a bit of a hoot to see if I could put it together and make it work. However... it uses Miller 6183 horizontal blocking oscillators as the 50 KHz if cans. Are these things available? Are there subs available? Do any of you tv experts know what the electrical characteristics are? I've been able to find very little info on the web beyond that they seem to be generally unobtainable. If that is the case, even if I could find enough I probably would not want to suck them off the market when people might need them to restore TV's.

Anyway, any information you can offer would be appreciated.
Paul