I bought the sheet cut to my specifications (Rectangle) and I cut the corners with electric shears.
Dimensions were 3' x 5' each
I shaped them by bending them aginst their selves. What I mean is that I set one end on the ground and bent the steel over until I reached the desired shape. I took a few tries but just take it slow and check it against the trailer often. It is difficult to bend but it will bend.
I trimmed them with some chrome molding from an auto store.
I had intentions of putting factory molding on them but the 1971 rub molding is not available. The molding is important because it provides for a stiffener. The shields will vibrate as you roll down the highway. The wind will make them "flap" and work the rivets loose. It is VERY important that you have fastened them tightly and eliminate any movement.
You will need a very good drill bit to drill holes into the stainless steel.