Don't know if the 960's will tolerate it, but sometimes you can file the slot slightly lower to allow brakes to reach a 700c rim...

Oops- I was thinking of 986's... I see on Velobase that 960's don't have a slot...

The only thing to do is to lower the straddle cable to rotate the canti's out and adjust the pads inward. But you've already tried that I assume. Plus that will change the pull ratio.