Most reputable independent tube equipment repair facilities in the US ?

Stereo Rehab in Chicago. I was thrilled to find this place...exactly what you seem to be looking for.

 https://stereorehab.wordpress.com/

On the east coast, I’ve had work done at both SoundSmith in Peekskill, and AudioClassics in Binghamton. Both provide excellent service and have the knowledge to tackle projects that others might not touch.

A quick look at Stereo Rehab yields this tidbit:

For reference, Stereo Rehab IS NOT accepting any units for service that are shipped in. Only units that are brought in, assessed and evaluated with the units owner present, auditioned in person by the units owner upon completion, and picked up in person by the units owner are accepted.

Too bad for all of us who don’t live in Chicagoland.

Yeah, no shipping is no go for most of us. Analogique in NYC doesn't do shipping either, by the way.

Prairie Audio does not exist on the web, at least I couldn't find it.

I'll check those places on the East Coast.