1965 Dodge Coronet Convertible Window

I have started the process of replacing the convertible top. The one on the car being restored does not have the back window (or any vinyl). I received the new top and new back window but I noticed that the window doesn’t have any vinyl at the bottom to secure to anything. I assume it connected to the underside of the trunk edge – but I don’t see anything under there for securing it to.

As part of the top, I received a separate piece with a round stick through it that looks like it can accept the window. It does fit into a channel on the trunk side, but it’s 6" below the top edge of the trunk. That would allow rain to get in and sit forever. Seems like something is missing…

Has anyone replaced the top and can provide some guidance?

Thanks for any input.