Hi all. I've just fixed some alignment problems with the rangefinder on my Agfa Isolette. The first thing that happened was that a piece of black cord came out through the front of the camera. I presume that this was a light seal. I've pushed it back in but is this enough? Or do I now have to do more dismantling to get it in the right place? Then I lost one of the set screws on the back of the rangefinder knob. It seems to be fine with only one, but will this be ok in the long term? If not is there any way to get a replacement? As this is my first camera repair, I'm a bit nervous about the implications of these mishaps. Chris B.