Many gunsmiths in the 50s, 60s and 70s would switch out the hinged floorplate on the 1904/39s for a standard Mauser floorplate. They would then use the hinged floorplate on the sporter Mauser they were making and resell the 1904/39 for the same price they paid for it. The reason is the hinged floorplates Mauser was selling was something like 10 or 15$ and buying a M1904/39 was about 10$. So for no cost they were getting a 10-15$ part for there sporters that they were selling.