I had the exact same problem with my 1940 half ton years ago. I do remember that I drilled it out and glued it on. I don't remember what kind of glue I used, but it's still on there and has never been a problem.
Mike Burns 1940 Chev 1/2 ton 1953 Chev 1/2 ton 1950 Studebaker Starlight Coupe 1947 Indian Chief 1943 Indian 741