My vac. advance on distributor 1 AP 4101 1 (from 48 b1b) has bad diaphram and does not hold vacuum. I have other Vac, Adv, units but this one is unique in that it has and off-set in the arm. I have heard of prying them open and replacing diaphram but would want to make sure it is the final shot before distorting what may very well be not replaceable. Is there a source for repair or replacement that may be available before I cobble up this one. I am using this set up on my 49 dodge because it was the only dist. for which electronic module was available at the time. Incidently the changeover to Electronic module went very well, but leaves me with no Vac. Adv. Thanks Ron