I have this lens, which had developed coating defects over time. I have asked guys at Focal Point, and got an estimate for repairs north of $600. I am wondering if anyone knows anything about these lenses and whether it's worth repairing it. I suspect this may be a lens, it's a "1Q" after all, but it may just as well be a very ordinary DDR tessar -- and they are quite cheap on ebay these days. Any advice is appreciated.