Over the past two years I've been gradually building up a medium format kit based around an RB67. I have bought a few things new (when on clearance prices) but mostly secondhand, and a few lenses have obviously had a hard life - shutter speed dial stiff, internal dust, worn paint. The general appearance doesn't bother me much, after all it's better to use a lens than to look at it in a glass case. The internal dust seems to be a feature of used Sekkors anyway, so again, not too bothered. One lens though has signs of over-zealous cleaning, very small circular scratches on the front element, that are only visible at the right angle in the right light. I keep telling myself 'this makes no difference to the image quality, this makes no difference' etc etc, but we all want our images to be the best we can make them, so I just need a little group therapy that it's all ok, that I can stop worrying, that I won't notice the loss of quality, then I can just go off and enjoy taking pictures. BTW, the jump up from 35mm to 6x7 is so amazing that I hardly ever use my 35mm kit anymore.