[Spanner]

I have these binoculars. On line research has given up a little information. These were made by Voightlander and Sons according to the letter code. These two things have been difficult to determine. Checking on line spread sheets and such I have not seen any with a 7 digit serial that begins in 1. Notice that the '1' is larger than the rest but lines up nicely. Also, I can't seem to find out what the triangle means. I'd like to know when they were manufactured and any other information that can be had. Just interested in the history of it.

Thanks for looking.