I would pretty much second Nancy Fratti's comments on the 17 1/2"
(probably 17 5/8") Symphonion, assuming it is a double comb (which I
believe they all were) and assuming it is in good unrestored condition
-- probably a retail of $4500 or so.

It is a scarce machine, and Nancy is certainly right about the discs.
We have had two of these machines in the upright format and finding
discs for them was very difficult.

Marty Roenigk
www.mechantiques.com