I too have been wondering about whether to media blast the fenders and hood on the '49. This morning I made a decision. After looking at the economics of the different paths to take.
I loaded my black and decker sander with 80 grit paper and sanded the loose rust off the undersides of the fenders and washed them with greased lightning soap and a brush . After drying in the sun, I painted the undersides with POR 15. Now I need to build a couple of stands for the fenders and sand the thin original paint off of them. And prime and paint.
Cleon