Original, probably 1920's flat tin toy soldier set. It is in reasonably good condition with some wear. One man is missing a head (still in the box). This set is called Preuss. Artillerie Feuer.
Ernst Heinrichsen Nürnberg produced lead figure designs from 1839 to 1938. They produced over 16,000 designs. Heinrichsen popularized the "Nuremberg scale" / "3cm scale" for flat lead figures.