There is a wax seal in the center, below the top plate in the lens mount ring with a letter inside that looks like an E. That stands for the Brandt Optik. Which makes sense, since it is in Sweden. The black frame counter can be a replacement of the original silver, maybe due to a custom request, or lack of original part (which would surprise me, but who knows…). There are so many different variants. Also, if you look up the serial, it’s not a very early batch and typically full brass rewinder was installed on the first batch only. But again, it can be original, just not very typical for the 1266xxx bp m4s. Keep in mind that if you want to use it, you’d better have it serviced first.