Either this Hemingray-16 went back in time to 1916, or the engraver got confused and embossed "16" where the date code should have been. More likely this was made in 1939 or 1940. Found in an antique shop in Wisconsin. Mold #25, smooth base.

So far, this is the only date code error I have seen. If anyone else has found one, let me know!

Update: A couple of people have suggested that maybe it was supposed to be "61" (for 1961) and the numbers got reversed. I think this is unlikely for two reasons: 1) By 1961, all CD 122s had a corrugated base (CB) - this is smooth base (SB) which was largely phased out by the 1950s. 2) In the 1940s, the Hemingray-17 was introduced; Hemingray-16 was changed to a smaller wire groove, and Hemingray-17 was given the original, larger wire groove. This has the larger wire groove but the #16 embossing, so it would have likely predated that change.