The Blue Book is worthless. Completed listings on Gunbroker are a lot more realistic. I just sold one of those, with Damascus barrels, for $400, although it wasn't quite as nice as yours. I would guess $500 topend for yours. One thing that hurts the value is that those guns have 2 5/8 inch chambers, and NOT 2 3/4 inch like more modern guns. Modern 2 3/4 inch plastic hulled shells will fire in them, but are recommended to be used sparingly, and nothing with high pressure.