According to SOR, the brake hydraulic parts changed for manufacture dates 9/71 and later. You should order for a 71 model year, by my research. If I were you, I'd verify with the tech department of whatever vendor you choose before buying.
Cruiser Outfitters also shows 7/70-9/71 as an option. I ordered late one afternoon and they shipped my order an hour or so later. They sell the good Japanese stuff which I know is generally much better in the long run. Also, Beno will know exaclty what you need.
I'm mostly sure that the bolt pattern for the wheel cylinders is the same from 7/70 all the way through to 1979. And given that the fittings that bolt the hard lines into the rear of your cylinders are rare, I'd consider upgrading to newer cylinders. My 2c.