On Thu, 28 Jan 2021 16:29:44 +0000, wrote:

Hmmm, a badly structured question. Hopefully it makes more sense now.

On 28/01/2021 12:12, wrote:
A bit of a long-shot but ... is there anyone out there who has restored,
is restoring, or has worked on a 19th century square piano?

No, but a couple of thoughts:

1) Try contacting local piano tuners; they might know someone. After
all they might have been asked to tune one.
2) If you have a musical museum (even if it's not piano specific)
nearby they might have restored a square piano and be able to offer
advice or point you at someone.
3) I've come across square/straight strung pianos in National Trust
(and other) properties and they have all sorts of experts on call.
4) This is a bit more of a long shot but I wonder if one of the music
colleges (Guildhall, Royal Academy, Royal College in London for
instance) might be able to help?