Sadly, Nikon and Canon are not as organized, and use completely unrelated serial numbers for every product. Because of this orderly behavior, it it trivial to figure out when your lens was made. Leica made lens number 1,000,000, a 50mm f/1.5 Summarit, on 24 October 1952, at which time they already had onver 100 years of experiance.

Variants - Nickel, chrome, metric, foot, heavy cam (11-BP) versions.

The original lens for the Leica Standard when introduced was the Leitz Elmar 1:3.5 F=50mm in a collapsible nickel-plated focusing mount with infinity catch. On the back of these models there is a hole covered by a black plug, presumably for back focus calibration.

Take that as a guideline and the majority of 'rare Leicas' is out the door, simply because they can be had for USD 100-200 Buy It Now price at eBay or Craigslist It is found on early Leica Standards as well. First of all, if it is too good to be true, it probably isn't true to begin with. A Leica-faked Zorki-1 with Industar-22 lens, the Elmar 50mm 3.5 look-alike.

50mm summilux serial numbers