Hi, everybody! <p> It would be very interesting to identify my LTM Summicron 35mm F2.0, # 1631461. I am a shooter, not a collector and do not have a good reference book except Hove pocket book. Some years ago I purchased this lens in Germany in ex+ condition. I use it on MP4 and IIIf and get razor-sharp pictures. This lens has screw-mount & bayonet-mount facilities. The bayonet-adapter is fixed to screw-mount with a tiny screw. As Hove says, LTM Summicron was produced from 1958 in a quantity of 577 units. In 1958 only one LTM 35mm Summicron was produced. I referenced the number of my cron (1631461) exactly to 1958. Pardon my language. Any comments would be appreciated.