Another big thing to happen esp. with the early plate items, Plating companies would by Nickle silver blanks for companies like international or Oneida, and plate them and put there own mark on the item. Not sure if this is what happened here, but your piece is for sure Post 40's silver plate, and very common plain look, made with very thin nickle silver base. One good thing and I'm not 100% sure but looks like a bakelite handle on the teapot.
