Infinity FET Preamp rebuild


I own a working ancient (1980 ish) Infinity FET Preamp.  This was quite a piece, back in the day.  It works pretty good, but is clearly overdue for a rebuild.  I live in So CA and I’m looking for the “right guy” to do this, help?
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The “right guy” would have been John Ulrick, the lead designer at Infinity Systems at the time. He also designed their class D amp known as SWAMP. He went on to form Spectron Audio. He passed away a few years ago.

The likely issues might be aged parts. The solution would be to replace all resistors, caps and FET’s with premium parts, and replace the internal wiring with quality Dueland wiring. Any competent service shop should be good enough to handle this work. Should not run more than $1,500 in parts and $500 in labor. 
I realize what you are saying.  You hear horror stories and this is a very rare piece, so I want to be careful who I take it to.
I’d recommend his accomplice, Arnie Nudell. Regrettably, Arnie has also passed away.