New question about country of origin stamp

[Alexander A]

I have a Long Branch No. 4. Here are the markings on the left side of the receiver:

No 4 Mk I*
LONG BRANCH
1945

Just ahead of that is stamped:

CAI ST. A. VT.
303-B-CANADA

Meaning that this was imported by Century Arms International of St. Albans, Vermont and presumably came directly across the border from Canada. Century was required to stamp the country of origin as well as the caliber. (The "303-B-CANADA" lettering is larger than either the original lettering or the importer's stamp. The importer's stamp and the "CANADA" marking were obviously applied separately.)