Date code, details of condition (like just how big IS that "chunk"?), barrel length, choke, any alterations like a cut stock or added Polychoke, etc. would be needed to get anything close to a real world value.
My guess is that it if it works, it's worth more as a shooter or just for "things that go 'bump' in the night" than it would be to sell it. Just my opinion, of course. (You just never know when you'll need a working pump shotgun....).
