CBC/Ross built, '73. Can't really see the 7 in the serial, between R and 3, but the BMA/6 decal covered '71- 79, and it would've had a Bendix "76" brake after '75. -Adam
I agree with the Ross built. The chain guard and fork are Baracuda-style. I bet if we dug into Ross ads for girl's bikes around the '72/'73 timeframe, you'd see the bike.