Here are mine. If you want to "borrow" them over the winter, we can arrange something. Mine are just like what you need for your smallmouth TR3. My TR3A is a very early one with the wedge mounts in the chromed supports.
They are in the bag I bought from John Warfield at TRA to keep them clean. My sidescreens were rebuilt by Larry Learn when he did them for Roadster Factory back in 1989. They are still like new.
Notice that the lower part is like a flap and if the 4 snaps are not securing the bottom, you can stick your arm out and hold up the flat for more ventilation on a hot and humid rainy day. The later sidescreens for the Dzus attachments do not have this flap. On those, that lower part is rigid.
PS - Don't just put them in the bottom of your "boot" and then place your heavy steel tool box on them. They will never last.