I have two older brakes that I need parts for.

One is a pair of nutted long reach single pivot Dura Ace brakes. The rear has a campy drop bolt which I don't need. Are these things pretty universal in terms of dimensions and so I can just buy a generic part like this, Pyramid Brake Pivot Bolt 42 Rear




I also have a pair of dia compe 450 centerpulls. I'd like to replace the brake shoes. Where is a good place to find a brake shoe that can fit the existing pad holders or can I get a pad holder to fit? The bolt measures 6 mm.