I think the configuration of the spring on the Diacompe is the breaker. I have a Centurion which came with center pulls mounted directly to the frame. I bought a set of Gran Compe brakes thinking the would mount directly but the springs are not the same. So the bike now sports Mafac CPs which fit right on with their standard springs. My Herse has brased on brakes also but they are Universal 61 with what looks to be standard springs. I looked at rebending springs but that is a tough job (or maybe I am not strong enough)
BOB FREITAS
sunny then foggy in MILL VALLEY, CA USA