I will add some info I learned the hard way a few months ago in doing the window sweeps on my ‘46, in case it helps. I had to try rubber products from two different vendors, plus use some of the tricks others reported previously. Those tips included cleaning and widening the channel, soapy water, then recrimping the metal using flat nose sheet metal pliers.
I started off using the Steele Rubber product, mostly because I’d had really good success with the windshield gasket and many others have reported the products to be superior. Well, It fit the channel ok, but it was too wide and the windows would not roll up or down effortlessly or smoothly. In fact, the rubber was binding. I had a short segment of the original saved for reference and noticed the width was different. Out of curiosity and mostly frustration, I ordered a replacement kit from Jim Carter’s. There was a .25” width difference between the two products, the JC Rubber is 3/8” wide vs 5/8” for the other. Once installed the windows roll up and down much easier, but the sweeps don’t touch the glass well enough IMO to be particularly effective in sealing out moisture.
