I am trying to put this old brake back on my road bike but am having a hard time getting it to really clamp down on the tire. At this point, it kind of slows you down.

Any advice? I have dealt with more modern caplier brakes with no issue... run the cable, turn the screw, tighten and voila. These seem to require something more.

I also have an issue with the top tube cable brazes-- one of them has rusted off. Is the way I have it set up in the photo ok? Does anyone have a suggestion about how to deal with this?