Illustrated historical reference · Insert
1947 51 — Insert reference (1947–1951)
Insert reference periods can overlap. Replacement inserts and transitional variants exist.
- Known period
- 1947–1951
Reference images
Evidence, source and dating limits
Sources: In Quiet Detail — Primary photographic and collector reference archive
Dating caution. This is a documented period reference, not proof of a precise manufacturing year. Case and insert can have different manufacture dates; inserts may have been replaced. A single feature does not establish authenticity.