I have a bit of a dilemma. I have an LTM ELMAR 50cm 2.8 ELMAR serial #1453607 which from all lists states a date of 1956 yet many websites state that the 50 cm 2.8 was introduced in 1957.
It's always the case with early or late serial numbers. I have a Leica MP that was made in 2002, but they weren't released until 2003, it's just creating enough stock to send to dealers on the release date.