I was looking at my old Calumet CC-401 yesterday and notice a hole in the bellows. It appears to have happened because the knob and spring that hold the gear which adjusts the front rise and fall are missing. I haven't had a chance to replace them yet and it looks like the gear has torn a small hole in the corner of one pleat. Bigger than a pinhole, but very small. So here is quandry. Since I am contacting Calumet anyway, should I see about getting a new bellows when I get the new knob assembly, or should I just patch up the bellows I have now? I have NO idea how hard it is to replace bellows. It appears to screw on with 6 screws on each end, but that is all I know.