I tuned my daughters piano teacher's 1917 Steinway O on friday.
She had moved about a year ago. Many of the hammers were shifted to the point of not striking all strings on the trichords and even a few striking a string on the next higher note. I had to remove the action and adjust all the hammers and tighten the flange screws. I didn't charge her for that since, afterall, my daughter passed her college auditions and was accepted to quite a few good universities, so I didn't mind the favor. The tuning came out quite well and she's happy.
Question is:
Better to remove the action when moving a grand. I think the movers put the piano down a little hard on the treble side when moving, causing this shift.