I'm rebuilding the Schwinn for my son's friend. After tackling the crankset I moved on to the brakes - I have a set of Shimano V brakes to install. The rear bosses don't have that 3-hole tab to secure the end of the return spring! They do have a small hole running parallel to the BB axle on the inside of each boss.

How do I handle that - other than go go with only front brakes?

Thanks!