It's probably two 1's, to make 11. Pre-'46.2 month codes were numeric, rather than alpha. That would make it November of '41, as '42 production, from what I understand, started in August of '41.
Curt ---- 1953 Chevy 6400, 1957 Chevy 2dr Sedan --"Mediocrity is easy, the good things take time"