Tony, Emil's right about the engravings "Serie" and "Series". Y'r lens' trim ring is incorrect, probably is, as he said, a B&J fabrication. There's no reason why the serial number on it is right.
Originally Posted by aoresteen
What Emil didn't tell you is that it seems that many of the lens elements B&J came by were rejects that weren't, for some reason, sent back to be remelted. This is why B&J's Dagors and other lenses are viewed with suspicion.
Y'r front cell may have been made by Goerz. Or it may not. Zeiss cataloged f/6.8 Dagors as late as 1933 (see http://www.cameraeccentric.com/html/info/zeiss_3.html) It isn't clear whether Dagors sold that late were made by Goerz and Zeiss removed them from stock as they were needed or were made by Zeiss. So your lens' elements could have been made by either firm. We know that Zeiss made some Dagor elements; I have a 45/9 CZJ Goerz Dagor that, according to Thiele, was made in 1937 to a 1934 design.