I have limited information and limited pictures....does anybody here know how to "date" a F. Williams sxs shotgun. It has hammers and I am sure it is damascus steel. I already know it was a gunmaker out of Birmingham England but have no idea how to "date" it. Apparently this is important because the fella wants to bring it into the USA from Canada and the date is a factor....I have no knowledge of these regulations, requirements or such. So I have read a little from Customs and Border Protection, along with ATF. The main question here is how to "date" this gun and prove year of manufacture.