Wikipedia
Siderius
Siderius was a company in the Netherlands during the 1920s and 1930s. The company was set up between World Wars I and II by Rheinmetall of Germany. Prohibitions against weapons production by that company had forced it to do business in other nations.
Siderius was dedicated primarily to the modernization of Krupp artillery in service with the Dutch Army. The most effective of its projects was the Siderius Model 02/04, a modification of the Krupp 7.5 cm Model 1903. Several were in service both in the Netherlands and its Pacific colonies. Parts captured by Germany in 1940 were employed in coastal defense under the German designation 7.5 cm Feldkanone 243(h).