On my '50 there were 4 scews holding tabs from the outside trim in the window seal channel (I think) - one front, one back. and two along the top. In my case one door had the outside trim and one did not and I had removed the window seal channel so it became clearer. The new outside trim piece I received had the tabs/screws in a different location. There are also tabs that slide into opening in the door sheet metal along the bottom.
I don't think if makes a difference but mine were painted rather than chrome.
