The two patent numbers were from 1925 (Griswold) and 1935 (Wagner) as I posted on another of your FB posts. I don't know, with such widely spaced dates on the patents and two companies being involved how the marking with the patents and dating would work. One would probably also have to know the date ranges that the 1402 was made. If it came out before 1935 I don't think the patent number(s) would be on the pans. And when at least one of the patents expired (7 years back then??) would Wagner remove both patents? Did Wagner and Griswold have some kind of agreement to use each others' patents? The same patents are on the Griswold double skillets, at least the No.90.