1917 (or 1937) Selmer (Paris) Tenor Sax

Looking for information on value of a 1917 or 1937* Selmer (Paris) Tenor Sax. My dad at 96 y.o. is now considering its sale.  We know it has value (previously offered 7k), but we are not sure what it is currently worth.  We would appreciate help in knowing its value and would consider its sale.  I can furnish pictures on request.  (It is in very good condition, but likely will need replacement of its pads).  Would appreciate emails first rather than phone calls.   ---Located in NJ---  Please note, I've been told it is a 1917 sax, but research of mine based on s/n indicates it might actually be a "Balanced action" Dorsey 1937 model.