The values in Blue Book of Airguns are estimates, not based on prices realized at sales.

I assume that this is a .22 cal gun. If .177, you've hit the jackpot.

I can't recall seeing very many, if any, sales for this gun. It's certainly a worthwhile collectable. $300-$400 would be my guess. Although rare, there really isn't a lot of demand for these, from what I can tell.