I just entered into the exciting world of adapting an old m42 lens. The lens I have, an Auto Rikenon 1:1.4 55mm (Ricoh Auto Rikenon 55mm F/1.4 - Review, specification and sample photos - AFLenses.net), mounts reasonably well onto the (cheap adapter) and sits tight inside the adapter. The lens seems to have a lot of metal. Unfortunately, the lens barrel of this fixed focal length itself seems to have an enormous amount of play - it can be pulled back and forth (about 1mm), wobbles quite a bit when touched (or used). This is easily visible in 14x magnification mode; the focus plane keeps shifting. The aperture ring, on the other hand, sits perfectly nice. The seller described the lens as being in good state. That does not seem to be right to me. Any comments on what these lenses should be like?