Hi, I have a rather beautiful pair of genuine East German Jenoptem 8x30. I just bought a case to go with them on the 'bay (the original flap-cover type in mahogany leather with red velvet lining). I know there was discussion on here years ago about Zeiss serial numbers, and a link to a P. Abrahams site with a serial number guide, but I can't access it anymore. Has anyone any idea how I could find the production year of my binos, serial number 4579710?