Hey, Andy - Both of my M6's continue to work just fine; I've had my original M6 for over 10 years and it's seen some periods of fairly heavy use. However, I love them and would certainly look at pre-ordering the apparently unavailable repair parts from S.K. Grimes to have them on hand, if a bulk order would reduce the individual order cost. I see that you've cross-posted on Rangefinderforum.com; if enough people are interested to make it cost-effective that'd be great.
Btw, it's interesting to see various posts elsewhere on the internet (see here http://www.flickr.com/groups/mamiya/...7608265940650/ for example) with claims that x-corp or y-repairer can repair Mamiya 6 "for years to come", although those claims would carry more weight if they weren't coming from someone trying to sell their M6!