Hi Bill,
Here is what I have found out so far. This item was made by Carl Zeiss Militarabteilung Jena Germany. The markings blc indicate this maker. The blue coloured + sign indicates could weather capability.
Now I looked at the photos your friend sent you and they are not of the same piece of equipment, the serial numbers in the photo here and on the ones in the email are not the same, also some other differences so I guess he sent you photos he found on line until he gets home to where the actual piece of equipment resides.
Now going by what I have found so far this scope was used by the Airforce as well as the Army so there may well be a data bank somewhere on line you can find out exactly which unit this particular set was issued too, the German Army kept very detailed records so you might be able to find out more through the Bundes Archives or you could contact Zeiss and see if they have their war time records available.
It was also used with the JadgTiger and JadgPanther. I will see if any of my photos clearly show this piece of equipment. This may take a while but for the most part the piece of equipment here looks proper and correct for WWII issue. Hope this is helpful
Dave