Here we go: (1) I would have to locate a rigid Summicron with a properly functioning focusing mount (and trashed optics to make it cheap), (2) determine that the focusing mount is indeed focusing properly, and (3) if the rigid Summicron is not exactly 51.9mm (as as is likely), I would need to arrange for shimming for proper focus calibration. All three steps would be virtually impossible to achieve in Bangkok at reasonable cost or in a reasonable time frame. The alternative would be to buy a really good rigid Summicron and sell my DR Summicron, but I am definitely not into buying and selling photo equipment, which I consider a great PITA. For me, living in Bangkok where there aren't the market nor the repair facilities that are available in the US for this, the solution of milling down the cam on my excellent DR Summicron, despite the fact that it is a gem, is more practical, particulalrly as this solution would also have the benefit of being usable for the close focusing range, without using the goggles, on the new Leica M by using the EVF.
Now, coming back to the subject of this thread, it seems to me problematic, the next time I go to the States for three weeks, to send this lens to DAG to get this done in the light of the experience that douglasf13 reports.
—Mitch/Bangkok
Bangkok Hysteria (download link for book project)