It's most likely a 1972 version since that curved stripe showed up a few years back then. First number of the serial gives a clue to specific year.
As for brace, it can vary from bow to bow and shooter to shooter, BUT I would put it at 7" to begin and experiment. Twist it up until you find the sweet sport which I bet is 7.5" to 8". Those are nice bows, and good luck with it. My 73 version likes 7.75".