Brian and co at Analog Room in San Jose would be worth a call. Good guys
Brian's previous tech, and designer of the Wavestream tube amps you see in the Analog Room is on his own. His name is Scott Frankland <audioeng@ix.netcom.com>, and I believe he would perform service on tube gear. He might need a schematic in order to fix malfunctioning gear, but for servicing I don't think so. He offers a proactive servicing plan where he will inspect and test the tubes, and estimate their remaining life. He will likewise inspect and test the electrolytic caps, and estimate their remaining life. He will check the coupling caps for leakage, the connectors and sockets for oxidation and tightness, and rate the overall performance of the amplifier after a bench test. If any adjustments are needed, then he would make them and give an estimate if any repairs are needed. No affiliation but he's a good local resource to have. He did help me with a few problems on a VPI Classic 3 in the past, though.
Another resource would be Mitch Singerman <itchmay1@yahoo.com>, but he's down in Southern California. I've never used him, but his reputation is stellar and I'd have no concerns about shipping gear to him. It's really not that bad from NorCal to SoCal. I heard recently that Mitch is having back surgery, so may not be available for a while.
Good luck.