Here's a link to Model A style webbing Frame Welt it can be trimmed to any width, I used adhesive backed foam for my 1937 Dodge pickup, like this 1 8" x 2" Neoprene Foam Rubber with Adhesive Back | eBay .

I used coil spring "helper" rubber for body mounts Superior RideEFFEX™ 18-1701 - Spring Booster | O'Reilly Auto Parts

Hope this helps.