There are subtle changes in the logos over the years. the prewar ones
were Marque depose, and that was continued into the early to mid
1950s, then the "marque" was dropped out of the logo. The "marque"
then appeared back with the Model 63 super champion crankset,
introduced around 1963. it was also put back on the Mod. 49 cranks
too.
there are many slight differences in tooling of the cranks as well.
here is a photo showing 5 different cranks, with different logos, the
top being the oldest to the bottom being a 70s model. look at things
like the "s" and "g".
http://bikeville.com/
Joel Flood
philadelphia, PA