Tyler @ TC Tubes has done some minor work for me in the past on my tube amps and I highly recommend him. He and his wife Chelsey are probably two of the nicest people I have ever met in the industry.
However, If you need work done that extends beyond basic servicing or a general tune up I would contact Jim Sawyer @ Sawyer Audio in New Brighton. I have used him for several years and he is fast, reasonably priced and extremely knowledgeable. I know TC Tubes also uses him for more complex and extensive repairs.