I think you might be giving me too much credit on that one lemme tell ya what happened.

As you know on those bikes there are studs brazed on the fork to accept Dia-Compe Centerpull brakes. There's a little metal tab with a "D" shaped hole that slides on over the post before you put the brake arm on. Its to provide an anchor point for the brake arm's return spring. On day after a ride one of the brake arms wasn't springing back to position. The little tab had rounded its "D" shaped hole off into an "O" shape and was no longer providing spring tension.

2 options. 1 - find or make a replacement, or 2 - Improvise.

I went with option 2 and guessed that Dia-Compe would have copied Weinmann's Vainquer 999 brake to the letter. Which means the back plate for a weinmann centerpull (which provides the same function as those silly little washers) should work with the Dia-Compe arms. It did. And being that the spacing was exactly the same between the arms the back plate bolted right up to the brazed on studs.

Originally the arms mounted about an inch or so closer to the fork crown. Now with the addition of that plate they sit far enough out to allow some Kool Stop Supra 2 pads to fit Admittedly an unintended effect, but a good one!