Here are the basic 1930, 1938 and 1940 sets with ratchets. 1930 to 36 used m70 (optional had to pay xtra). 37 38 had m70n ratchet, no screws in ratchet head. 1939 on m70m ratchet with screws in ratchet head. Probably other variations after that like m70l,pm70, but those are kind of the standard versions.