The first time I removed the original radio from my 1954 3100 1/2 ton, I saw it had a thin fiber board cover that attached from the top of that tall speaker and went down on a 45 degree angle past the back end of the radio. It was very weathered. It looked original but I couldn't be sure. I found a thin cardboard box with a sealed surface on one side and made a new piece to replace the old one. It sheds moisture that may get in some way. The 54 also has the cowl vent drain hose down the firewall in the engine compartment.

Stovebolts are good for the heart