Two base types were made, with various cavity numbers and auxiliary lettering.
Big 5a Base 1, "A-1"
Big 5a Base 1, "A-1"
Base 1:
"A - 1" or "A - 2" first, with S4-D below it. Used ca. April 1939.
A-1 [A-2] S4-D
Big 5a Base 2, "A - 1", no auxiliary lettering
Big 5a Base 2, "A - 1", no auxiliary lettering
Base 2:
S 4 - D first, with "A - 1" or "A - 2" below it. No auxiliary lettering. Used ca. June 1939 to ca. early 1941.
S 4 - D A - 1 [A - 2]
Big 5a Base 2, "A - 2", Z 5 #1
Big 5a Base 2, "A - 2", Z 5 #1
Big 5a Base 2, "A - 2", Z 5 #2
Big 5a Base 2, "A - 2", Z 5 #2
Base 2 "Z 5":
Like base 2 but with auxiliary lettering "Z 5" rotated 90 degrees, located on the right side (for A - 1) or left side (for A - 2). Used from ca. early 1941 to ca. April 1946.
S 4 - D A - 1 [A - 2] Z 5
Big 5a Base 2, "A - 2", Z3
Big 5a Base 2, "A - 2", Z3
Base 2 "Z3":
Like base 2 but with auxiliary lettering "Z3" rotated 90 degrees, located on the right side (for A - 1) or left side (for A - 2). Used from ca. May 1946 on.
