Hi from Italy, on the italian website partner of binomania.it, astrotest.it, we have published (english version) a great article of Giuliano Tallone regarding the Zeiss Telescopes Serial.
I hope it's of your interest. If you want to use google translate, you will also find other articles and reviews. I am loading them slowly.
Edited by Binomania.it, 02 August 2020 - 04:01 AM.