A few months back i acquired a Leica IIIG from a well known auction site, body only as I has a suitable similar era Elmar F2.8 doing nothing and I even had what I think is the correct leather case for it. I had contacted the seller and asked a few pertinent questions and even suggested they make sure they cock the shutter before changing shutter speeds, which I think they knew about anyway. I was very pleased with it's overall condition when it arrived and soon put a roll of Ilford HP5 through it and eventually developed the roll and was very pleased with the overall results. Interestingly a little later I put another roll through and was a tad surprised to notice, as I hung the negs up to dry, that clearly some frames, probably nearly half the film, were showing distinct signs of curtain lag. In other words this problem sort of manifested itself really quickly. Added to that from memory I was using the same fairly high shutter speeds with both films. The camera is now away being serviced. I don't object to it needing attention but slightly surprised just how quickly the fault developed.