These are a bunch of things I’ve been pondering for a while, and the recent acquisition of a 360 Berlin Dagor has finally spurred me into action. First of all, I can find relatively little historical information about the German Goerz company other than bits that relate to the American subsidiary.
I’ve got the typical list of Goerz serial numbers (the Eddie Bolsetzian list) that everyone uses, but I don’t know for a fact if both companies used the same scheme, particularly after the takeover of the American branch during WWII.
I’d also like to know if there were any differences in the design or materials of corresponding lenses between the two companies. For instance, my 360mm Berlin Dagor (344,xxx) has an aluminum barrel, and as far as I know all Am. Opt. Goerz Dagors used brass barrels. If there was a difference in materials, could there also be a difference in design or performance?
Why did some early Berlin lenses have apparently two serial numbers? I have an early 240mm Dagor, and it has both 74,xxx and 90,xxx numbers on different parts of the barrel. I also wonder about why the product lines differed (mostly because I'd love to find a 180 f9 WA Dagor), but I’ll stop here; any enlightenment anyone could provide would be welcomed.