I've got a super ikonta BX with f/2.8 coated tessar, in the older compur-rapid shutter. I need to remove the front element to clean an internal surface of the lens of fog. THe front seems to be held with two micro screws, but I'm afraid if I remove them and pull off the front that I'll uncouple the rangefinder or throw it out of calibration somehow, as the rotation and movement of the front element is what focuses. Any tips? It looks like there's a tab on the side that slots into the rotating front lens barrel, and might be the rangefinder coupling mechanism. Ideas? Anyone done this?