I have one exactly the same Nos with the plastic washer, too. However, it is impossible now for me to do anything since I'm in vacation till 30th of August...If you still want it after that date send me a reminder
Jeeze, what are the odds? My brake booster went bad and I just got a replacement from APE that I'm planning to install on Saturday. If I don't bust anything in the process I'll send you the elbow off my old booster. PM me your address.