The Bismarck razor company was in business from 1900 to 1930. Dorp & Voos, which became Dovo, bought them out and continued to use the brand name. This one has some surface rust but overall, it is in great condition.
This one however, was passed down through the Viljoen family and no one seems to recall who exactly owned or used it. I guess back then, what you did behind closed doors, remained there!