<p>Great write up and pics, Daniel!<br /> I have a 635 too (without the 35mm kit) and after the first few rolls, noticed a similar notch in the right side of my frames ... I was pretty sure that it was one of the aperture blades (lol) ... then one day, absent-mindedly fiddling with the camera, I realized that one of the knobs on the left side could be pulled out, and rotated to stay out - of course, it was the 35mm film release knob!! <br /> No more notches after that - and of course no more absent minded fiddling or that knob could go back in without me noticing!</p><div></div>