Hello George,
Thanks for at least some attempt at a description of the condition of your shotgun. It is better than most we get. At lest I have someting to go on. You are correct on the year.
Their are a few things like vent rib or fancy checkered wood which have an influence on the value. You didn't mention them so I guess yours is not. Without a bit more info I would most likely say yours would be in the $400 to $550 range. Really nice ones might get close to $750. That is a $700 gem below.
Hope that helps
2bit