Regarding Rick Olson's inquiry "... the approximate intro date of the Weinmann 500 brakeset? ..."
The 1957 Holdsworth Aids to Happy Cycling catalogue lists Weinmann Standard (730) and Shallow (500) brakes. The 1956 catalogue lists Weinmann "...standard or shallow front stirrup..." which would be the 500. The 1955 catalogue lists "Weinmann. Quick Release... " with no mention on standard or shallow or model number.
Peter Brueggeman
La Jolla California USA
4peebee(at)peterbrueggeman.com