Nice Boker humpback model, and the first one I have seen with that handle type. While Boker was using celluloid early on, they really pushed their "Pyralin" (celluloid) handles in different colors from the 1940s through the 1960s. They specifically called the handles on your model "Pearl Pyralin". I only have one illustration showing a red Pyralin handled humpback model from 1958 and assume that while many other Boker models featured Pyralin handles, the humpback types with those handles were not common. I would think that your model probably dates to around the late 1950s to early 1960s era.
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