A very fine camera, the f2 lenses (Schneider Xenon or Rodenstock Rodagon) are quite good for their time. As others have suggested, treat the winding mechanism with respect and care. Operate it slowly, steadily and never force it. At the end of the stroke you will have to overcome a small resistance, when the shutter is cocked, that is normal. The frame counter will count backwards and the winding lever will be blocked when it indicates "frame 1". You can only wind again after resetting the frame counter. Leave the film unwound/shutter uncocked when you put away the camera. I recommend getting a PDF manual from butkus.org to get accustomed with the operation.