>> ... Never seen (or perhaps never noticed) a Zeus part stamped "C" before (could the "BS" be worn away? <<
There's an interesting posting in the CR archives dated 11/18/2001 by Bradford Stockwell entitled "Dating Zeus Cranks, '70 to '82" in which he hypothesizes on if/what date these marks might refer to, and asks for corroboration.
I have 1 "a" with the early Zeus-in-globe logo, 2 "c"s with later Zeus-in-oval, 2 "f"s NIB set Zeus-in-oval, 1 "m" Zeus-in-oval and 1 "n" Zeus-in-oval. All have BSC markings.
By Brad's thinking these would be 1970, 1972, 1975, 1982 and 1983.
Paul Lee
High Point, NC