Thank you for your patience.
I assume that the serial number you have given has an extra digit in it, as the serial numbers listed for 1933 have 5 digits and start at 83500 and for 1934 they start at 85000.
Firstly to put things in context: the Antique Piano Shop pianos are generally total re-built restoration pianos using the best quality material available to bring the piano back to an almost as originally made condition. Thus with their reputation they tend to have quite high prices and, of course, as you touched on yourself, it is highly unlikely that they achieve the listed prices.
Your Schiller Baby Grand dated to 1933, is now approximately 82 years old. You have stated that it has been ‘’re-finished, the interior fully restored. New strings, new hammers, new pins and pin blocks, new felts’’. It is still possible that not all major components, such as the soundboard, were replaced or restored which would detract from the value. Also the restoration was approximately 10 years ago so there will inevitably be some depreciation due to age and usage.
From the picture I can see that the external condition of the casework on this piano is certainly very good.
Therefore based on the information I have, the condition as described and as viewed in the picture, the age, the style of the piano and the current markets, I believe this Schiller Baby Grand Piano has a value in the $7,000 to $8,900 range for a private sale. It may attain more in your locality but that will depend on the piano market there and a full hands-on inspection would be the only way to be absolutely certain. If you were to offer it to a Dealer then the price could be some 30% to 40% less than these figures.