I am looking for a Carl Zeiss Tessar-lens, about 30cm. Most of them seems to be made in Jena, a few of them in Wien/Vienna. I have found some information about the Jena-lenses but almost nothing about the Tessars made in Wien/Vienna. Does anyone know where to find information about the Wien/Vienna-lenses? Are they different to the Jena-versions of the Tessar-lenses?