Is there a date/serial number list for Leica lenses after say, 1984? Can't seem to find one on any of the Leica sites. On a 1950's lens, I can find out what time of the day it was made, and what they had for lunch that day at the factory. With modern lenses, it seems to be impossible to find out anything except a general time-frame by certain lens markings. Does a "modern" date/# list exist? THANKS!