What is the estimated value of this gun? How much would the value change if the chokes were opened?
Not sure who you're asking but since it's my gun, I'll take a stab at part of your question. Given the overall quality and condition of the gun I would think it should be worth somewhere between $900 to $1,500 to the right buyer*. The gun would be a tough sell, though. It's not a brand that collectors generally seek and it's not the type of gun that would appeal to modern shooters.
There's a very limited market for this gun. I suspect the question isn't really how much would changing the choke lower the value. The question is whether changing the choke would make the gun more or less saleable. Would potential buyers walk away simply because of the choke change? Does changing the choke severely limit its appeal to vintage double gun enthusiasts? Or, given that this is a gun that might appeal to hunters/shooters would a different choke configuration make it MORE marketable?
* If you accept the premise that the value of anything is what buyers are willing to pay then the lack of bidders in the auction I won suggests the value of this gun is quite a bit less.
