I don't know if it always holds true, but the first digit of the serial number on my Brownings match the year they were made. I would start out thinking that it is a '73. If I remember right, Browning added two 1/4" quiver bushings in 1974(?), your bow does not have the quiver bushings does it?
I love my Brownings, they are very fast for their weight. My 13 yr old daughter was getting 135 yards out of her 25# Browning Mohawk at last year Pope & Young shoot, shooting 308 grain Easton X7's during the womens 140 yard clout. Shocked everyone, myself included.