Precision fidelity C7 preamp

 Is anyone able to refurbish this? What would be good replacement tubes? They now  have  Sylvanias in the phono section( I replaced GE's).
I had a C7 in the late 70's. I liked the sound with the GE tubes! If you can afford it either NOS Mullard's or Telefunken's would be the ne plus ultra choice! Beware of fakes! 
The C7 was my favorite phono stage from 1978 to 1983. I stupidly sold it when I needed some fast cash. At the time I also had the much-esteemed PS Audio III phono stage. As good as that was I much preferred the C7! In fact, the C7 first appeared as the phono stage in the Precision Fidelity C2 preamp. Bruce Moore was the designer. He also designed the earlier Paragon tube preamps - the 10 and 12. So you have a true classic in the C7!
The C7 does not have a high-level stage. It is phono-only! The volume control and source selector function passively with no gain for high-level sources (tuner, CD player, tape deck ...). I preferred using my C7 strictly as a phono stage into the high-level inputs of the various SS preamps I bought and sold over time.
Audio Classics in Vestal, NY is my recommendation for repairs and restoration of HiFi gear. But if your C7 is working and sounding fine I would be content to leave it alone. Just do some tube rolling! 
sad news: The unit is now non- functional . I powered it up and instead of a tube blowing, sharp static like  pops are now emitted from the circuit board(like a light bulb blowing up). There also is a strange glow under the circuit board. The music still plays in stereo!
I ran the unit flat out and controlled the volume from the powered speakers. I had a deep soundstage but i dealt with some tube noise.

Fix it? ..Replace it with a Bellari?; I fi?, Schitt?..some other unit?
Sell It as is ?