http://www.rangefinderforum.com/forums/showthread.php?t=39491 It's a simple procedure to modify - there's one tab that engages the frameline selector it's the only flange at right angles, I believe. Simply take this flange straight back a little at a time, continually remounting it until the 35mm framelines pop up instead. It you take it too far, the 28mm framelines will come up, so be careful. Ideally you'd have a 35mm lens already to compare the flanges. It's a very subtle different. I would recommend covering the rear element with masking tape before filing to prevent any metal shavings from getting in there. Modification is easy like sockeyed described, three additions though: (1) I recommend taking the mount entirely off before you file, that way you don't get brass on the glass. (2) no worries about filing off too much, the 35mm frameline is brought up by the shortest flange on the M6 (it goes like this with decreasing length: 28/90, 50/75, 35 /135). (3) if you ever want to use it on CL or CLE (an even better fit) don't shorten the flange, since the CL/CLE 40mm framelines are triggered by the same flange length as the M6 50mm frameline.