OT v-e-r-y, to the piano players

We have a very fine old piano. It's a Steinway. Certainly it would like to
be gently tuned. The E flat kind of makes my eye teeth cringe.
Since things change so fast I suspect that piano tuning has advanced to
levels beyond my comprehension.
How do I go about choosing a tuner? I don't want my precious treasure
harmed; won't even have her tuned if it would be stressful.
What do I ask or look for? Polly