Various groups of lettering and/or patent information is on the bases.
Big 3 Base 2 "A-1"
Big 3 Base 2 "A-1"
Big 3 Base 2 "A-2"
Big 3 Base 2 "A-2"
Base 2:
Six lines of text with "A-1" or "A-2" at the top and "RD. 1931" in line five. Used from ca. October 1931 to late 1933 (or possibly into early 1934).
A-1 [A-2] PATENTED U. S. A. MARCH 29, 1927 PATENTS PDG. RD. 1931 69
Big 3 Base 3 "A-1"
Big 3 Base 3 "A-1"
Base 3:
Says "A-1" or "A-2" at the top and "69" at the bottom. Used ca. mid 1933.
A-1 [A-2] 69
Big 3 Base 4 "1"
Big 3 Base 4 "1"
Big 3 Base 4 "1"
Base 4:
Says "69" and "1" or "2" at the bottom and "C.D.C." oriented at right angles near a mounting screw. Used ca. mid-1933.
69 1 [2] C.D.C.
Big 3 Base 5 "1-A"
Big 3 Base 5 "1-A"
Big 3 Base 5 "2-A"
Big 3 Base 5 "2-A"
Big 3 Base 5 "2-A" Gunmetal Bottom
Base 5:
Says "1 - A" or "2 - A" at the top and ""69" at the bottom. The "1" or "2" and the "A" look crooked. Used ca. late 1933 through the end of Style 3 production (1934).