COBRA 50" 1969
COBRA I 50" 1969-75
COBRA II 58" 1969-75
based on serial number I expect yours is 1970 and a COBRA I bow. I think the first number represents the year in each series...the rest of the letter/numbers...who knows! LOL All within years of manufacturer.....for each model of course.
Mine are
Browning Wasp, 5T12100 1975
Browning Explorer I, OD233-1 1970
Browning Cobra II, 3N2152 1973