I bought a box of cameras and assorted junk from a thift shop and this was part of it. I'd forgotten I even had it at all until I came across it this morning when I was looking for something else.
According to The Land List, the 400-series are basically 300-series cameras which use an updated flash unit. So this is an updated 320, which was a rangefinder version of a 210, which was a color version of a 104. Hope you got that because there will be a quiz later on.