"Danzig" didn't exist in 1948, it had been returned to the Polish state as the city of Gdansk. The Prussian arsenal that manufactured small arms and marked them Danzig had not made guns since WW1, the factory and its tooling were inherited by the Polish government and used to jump start production at Radom, in Warsaw and Lwow. If your rifle is marked 1948 and Danzig, I suspect some good photos will be the only way to give you more info.