Hello, I recently acquired a Rochester Optical and Camera Co Tele Photo Poco D camera. Both sides of the bellows have two leather tabs with a metal ring in them. I have seen in photos that these rings loop around an anchor on either side of the front standard to pull the bellows tight so they don’t sag, (at least that is what I am guessing). If I am right my question is this. On each side there is one that is further forward and one that is a bit further back. When do you use one or the other? As this is a Tele Photo Poco it has a double extension bellows and has a rated draw of about 16 inches though I have not yet tested that. Thank you!