I recently purchased a Mamiya Pro TL body and also a couple of standard 80mm lens. One lens is not very pretty and has some dust inside, but otherwise seem to work fine. The other one is in very nice condition except for a short hairline fracture on an inner element on the outer edge (probably from a drop since the filter threads are bend). First question is which lens should I keep and second is there a way to test the impact of either imperfection, i.e. dust or fracture, on photo quality? Thank you for your help!