Not sure how to describe this. I have a Mamiya C220 Professional with a 80mm f2.8 lens assembly that is missing the linkage between the aperture dial and aperture setting. Does anybody have an idea where I could find this part. Or maybe even better, does anybody have such a apart. As the photo shows the screws are there. Someone in the past must have disassembled this and forgot to put it back on or used it for another lens. Any help greatly appreciated. Thanks in advance.