Originally Posted by John Shriver
According to Puts' book, consumer Hektor 135/4.5 lenses were coated starting at serial 600000. Wartime lenses were coated as early as 1941, but only for sales to the military. (For instance, Summitars for the military were coated starting at 587001.)
John, thanks for the information from Puts. That's the first printed information of it's kind that I'm aware of and it dovetails nicely with what I had suspected about the coating of Leitz lenses. One explaination for the way it was distributed is that lens coating may well have been a military secret. It's also possible that the process wasn't sufficiently developed to allow coating of all lenses.