I'm sorry if I'm a bit behind the thread, but I'm just catching up on
email.  Lynn Bullock's note about finding out the reputation about a
piano tuner and not relying on whether they are Guild members or not
rings true, but I would note that relying on a reputation is not enough
-- from whom do you take recommendations?

When I hired my piano tech to restore my 1923 Knabe, I interviewed him
thoroughly and inspected his work.  I made an appointment to go to his
workshop and saw the pianos that he was working on and the quality of
his work.  I asked him about materials that he uses and he went off on
a spiel about the benefits of hot hide glue.  I looked around his
workshop and didn't see any evidence of white glue anywhere; there was
cement for ivory epoxy and white powder to fill in chips of ivory, and
hot glue.  I asked him also about French polishing and he demonstrated
how he does it.

Over the last couple of years since meeting him, we've also discussed
good and bad technicians.  While I've heard of the reputation of one
particular tuner as being good, my tech told me that he now only tunes
the pianos, the rest of the work he leaves to his assistant (that's
logical because he's completely blind).  The assistant rides on the
reputation of the master but, for example, he has never heard of hot
glue.

Reputation is good for a start, but it's important to fully interview
anyone that you're considering doing more than a simple tuning.

Eliyahu Shahar