Robert - I'm envious, since my oldest Goerz is a 10 3/4" Goerz Double-Anastigmat Type B, Series 1c (No. 5), serial #140xxx. My oldest actually marked Dagor is another 10 3/4" f6.8 serial #150xxx. So does anyone have an idea at what serial number Goerz started using the Dagor name on the lenses? Also, were the early Goerz US serial numbers all used? Were there 30,000 lenses made between Robert's #120xxx and my #140xxx? Did Goerz make (and number) 120,000 lenses before Robert's, or was the first digit in the number meaningless and the first numbered lens was actually 100,001 or maybe 110,001? I understand there aren't actual records of early Goerz serial numbers. However, knowing the numbers on lenses older than Robert's would be interesting. Does anyone have a US Goerz with a 5 digit, rather than 6 digit serial number?