First thing you need to do is determine the manufacturer and series number (serial number does't help as they repeat themselves in each series). Did he save the stock and handguard? Saving all the hardware is good! I'll let the experts give you the bad news on value. Once you know the series and maker, you could put a WTB in one of the forums.
Good luck!

Dean (the other one)

Sporterizing. Turning a $600 original M1917 into a $200 sporter.