Just to be sure, look around the door opening on the inside. The late 49 (I personally have never seen this particular thing split mid year) and up would have a metal channel that is welded to the cab. It goes completely around the door opening. If there is no channel you would have a strip of metal that looks like a miniature version of the bed strips that go over the wood. This channel goes over the top of the rubber with screws going thru it. Of course the rubber is different from the early and the late.