Working on installing new glass and weatherstripping on a 1950 Chevy 1/2 ton. Single glass, pull down outside door handle...

Installing the new weatherstripping channel for the glass I see that the door is missing a channel inside for the weatherstripping to fit into.

The driver side door had this channel in it, but the passenger side does not.

I see where the channel is available for 1951 - 1955 1st but not for 47-50.

Any idea where I might find this missing piece?

Can I adapt the later model channel to fit the door so something holds the padded weatherstripping in place?