Hello
So we recently just purchased a W. Adams and Sons pitcher and matching bowl set. They are both in the Columbia pattern. On the bottom of the pitcher is simply the stamp with Columbia and W. adams and sons. On the bottom of the bowl however there is the same stamp, but off to the left there is a number 7 all by itself. I was researching on the internet but could not find what the numbers meant, I only found a matching bowl with a 13 on it. Would this be a type of serial or set number before the system set up in 1842?
Thank you