Thank you, everyone for your input. I have a couple questions.
Raimey, I found a couple of inferential statements elsewhere that the stamp of ##.## was month and year of proofing and the adjacent numbers were the sequential number of the proofing in the records of the proof house. Is this correct? I haven't been able to find a declarative statement that this is the case.
ChiefShotguns, I agree completely but fancy and scarce has a better chance of value than plain and common.
rtenenbown, I have registered for an account over there. Thanks.
Everyone: Any thoughts on how to establish a value? Rule of thumb pricing? I have not been able to find a mate to this shotgun having sold so is type comparison a reasonable approach?