Dan,

Don't mind me, just working towards my goal of 4000 posts!

They do make the "toe boards" for these cars. This is the metal that goes up the floorboard a bit. But if you need only small patches, good flat sheet metal can be trimmed and massaged into place as well. Get a plastic body hammer (Harbor freight has them - cheap) and when you tack a spot, use the hammer to massage the metal between welds to get the metal to shape. Trying to do this with the metal flopping around is near to fruitless. Tack, hammer, tack, hammer. You can flow a flat sheet into the shape you need that way.

Good luck and we're here to help - no burgers needed!