$150 to someone who really, really has to have one no matter what and is not willing to look any further than you. $100- maybe $125 to most everyone else- especially considering the condition.
A gun shop locally has one with more finish than you indicate for $125 and it's been on the rack for a couple of months. The age, condition, fixed (probably Full) choke, likely plain barrel, and unusual look will turn off most people. Unfortunately, it doesn't have much collector interest and the condition sounds poor so the value will be pretty low.
