Gun looks to be essentially the equivalent of a Merkel 47 (47E if with ejectors). Condition looks very nice. I'd say low teens with extractors, high teens with ejectors--if
it's as good as it looks in the photos.
I second Larry's opinion. The receiver shape and engraving are quite similar to my JP Sauer that was made in 1953 at the Fortuna factory in East Germany.
I see your new pictures. It has 2 3/4 inch chambers and it was made in January 1954. Nitro proof marks naturally.
By any chance does it have a number 1 inside a triangle on the side of the barrel's locking lugs? If it does, that indicates that Simson considered it a number 1 quality grade.
Bryan