does anyone know the worth re Ferdinand Schaaf piano circa 1850's?

[harrietjones]

FERDINAND SCHAAF UPRIGHT GRAND; FULLY REVISED: Purchased in Switzerland in the late 90's, redone by a Swiss conservatory trained and federally certified "facteur de piano", of the mark: Ferdinand Schaaf, Frankfurt-en-Main, registered as built in 1850 ('s, can't remember date exactly). Facteur de piano, Patrice Scavanni, Lausanne, SwitZerland, took the insides of piano to his atelier and redid all. In tune, playable. Box in very good, not perfect condition, needs buffed out.
Googling the marque leads to very little information. I am needing to sell it and trying to get a lead on someone who can help me to assess its real worth. I have had it locally appraised in an area which will not give its probable full value. A consigner is going to sell it for me nationally and we are struggling to put an appropriate price on it.

Anyone know who I might contact?