I checked three chemical compatibility charts and all suggest that
silicone is resistant to acetic acid, including glacial acetic acid,
so it does not sound like acetic acid will help to remove it.  I have
some glacial acetic acid and some silicone so can test it but it is
probably pointless.

Testing with vinegar can be done safely, but glacial acetic acid is
very dangerous and could do a lot of damage to both you and the parts
you are trying to remove the glue from.

It is probably best to remove the silicone by cutting and scraping.
Fortunately, silicone requires a very clean and dry surface if it is to
stick well and most slobs who would use it on a player piano probably
would not have prepared the surface well, making it easier to remove.

The big problem with most silicone adhesives is that they migrate into
wood, leaving an oily residue that is very difficult to bond to with
other adhesives; just a tiny spec of silicone remaining on a surface
will have disastrous effects on most auto finishes.

Silicone removing solvents used in the auto refinishing business are
quite expensive but the main ingredient (if I remember correctly)
is VM&P Naphtha which is cheap.

I recently sealed the faded plastic trim on my Sprinter (there is a lot
of it) with a sealer that contained silicone.  This was a mistake as it
prevented the subsequent application of oil based sealers that promised
to work a lot better.  So I had to remove as much of the silicone
residue as possible and naphtha seemed to work very well.  Removing
penetrated oil from wood might be more difficult.

Spencer Chase
Garberville, California