Nice observation thank you Simon. Do you think the shutter is fragile to the touch of a thumb or fragile in general use?. I know it would not be a good thing to poke a finger at a fabric shutter either. What is fragile about about the mount? I seen Nikon lenes stamped with a C meaning it was made to use with a contax different foussing then nikon without the C stamped I could be wrong. Lets talk about repairs for a moment not to get off the subject. I would think Russian repair people would have a great deal of knowledge on these cameras. Just trying to keep poorly made kiev 4s just running. I should be a breeze for them to work on a nicely machined contax. I'm sure in most cases ribbons are rotted and the camera just needs cleaned not really requiring parts I understand the russian kiev uses thick shutter ribbons and inferior parts for poorly machined kiev 4 cameras. (not all bad I hear) The one I had was. The shutter would open while changing the shutter speeds. I think there could be a savings with the right ribbons and repair person instead of a pricey 2 year wait here in the US. I don't think contax camera can never be recreated today in a modern factory to the same qaulity of the past. Once the older skilled repair people disappear this will spell the end of some of these great creations.