It's a Whitney spinet. Perform the last rites and move on! :D
But, since you asked...could it be something fallen in the action? Either a pencil in the stickers, or some stiff paper in the hammer butts? That would quickly explain why it's worse above C6. If I saw this piano, I'd explain to the owner that it would take significant work
to be able to
diagnose the problem. IOW, you'd need to replace the grommets and do key easing just to be able to do any of the normal diagnostic work.
I had a similar conversation about a Baldwin Hamilton with sluggish keys. I
thought the problem was most likely in the key sticks, but
explained to the customer that the only way to accurately diagnose was to address the excess key friction first, then see what friction remained. So I vacuumed out the mouse debris, cleaned the balance pins, and sized all the bushings with a soldering iron broach, but there was still excess friction in the action centers. I explained to the owner that, while I was absolutely certain I could fix the friction problem, it was uncertain just how much that would cost. I didn't recommend we continue. She took my advice, paid me, and I went on to the next appointment.
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John Formsma
New Albany MS
"Sneak up on optimal."
--Ron Nossaman
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