This was likely an manufacturing error.
Vintique's headlight lens molds (as well as taillight lens molds), as I understand, derive from the OEM supplier to Ford, and (until at least recently) were molded by that supplier. Someone in the 1950's - early 1970's (Greenland ?) acquired one copy of each mold, and later Vintique bought out that company. In talking with an ex-employee of Vintique there are stacks of un-identified (mostly non-Ford) molds in storage at Vintique.
The original OEM supplier had multiple molds, the one or two digit number at the top or bottom of the lens is the cavity number. The replacement lens has the cavity number that randomly survived.