Well,
I got my cargo cover back yesterday and threw it on the truck tonight after work just to see how the modification went. I don't have anything secured yet, but it's not too bad. I've never seen too many of them on the trucks up close and inspected them to see how they fit, but it seems to be still about 3 to 4 inches too long. But that's ok, I would much rather have it 4 inches too long than even 1 inch too short!!!! The seams for the end curtains hang down from the front and rear bows about 1 1/2 to 2 inches at each end of the truck when it's centered.
I think I'll call McMaster Carr and order some super-rope for it so I can get it tied down properly before the rally. There is some super rope at the corners and on the end curtains, but just rope on the sides so it shouldn't take more than about 26 to 28 feet to do the remaining little bit.