I was wondering if someone might be able to help with a few SR3 questions specifically related to the film gate. In looking at some SR3 images I've found online, I noticed that in many of the pictures, there is what appears to be a small screw mounted a few millimeters above the center of the gate. Some of the documentation I've found has described this as an adjustment screw for viewing screen height / frameline position. Was this adjustment screw present on new SR3s from the factory, or is it usually only found on modified or overhauled gates or cameras? The reason I ask is that this seems like the last place you would want to mount a screw, given its proximity to the film path. I'm guessing that the screw must be flush mounted or recessed, but it seems that even a microscopic burr on the screw head could potentially scratch the emulsion and be disastrous. Is this a valid concern, or are there safeguards in place to prevent film scratches?
Secondly, I've read about some SR3 gates "without top or bottom rails on the gate". Can someone explain what this means, and if it's a feature on all SR3s or only on upgraded or overhauled cameras?
Thanks to anyone who can help!