A braided strap is totally unnecessary unless you're going for some sort of show-winning concours restoration. With a 12 volt system, that's impossible anyway. Funny thing about copper wire- - - -no matter whether you shape it into a flat braided strap or a plastic-insulated cable, it still carries current! Just reconnect the cables, red to the insulated post on the starter, black to any convenient ground such as one of the bellhousing attaching bolts, or the starter-to-block attaching bolts, etc. Then run a flat braided ground strap OR a heavy wire connection from the block to the body or the frame (or both) to assure the lights and other accessories get a good ground path. The trick is getting the current back to the battery with the least amount of resistance. Once the main cables are sorted out, then track down the burned/damaged wiring and repair it one circuit at a time.
You're almost certain to have to replace the alternator- - - -if the battery was connected backwards for more than a couple of seconds, it's toast! There are 12 volt batteries made that will fit the original under the floor box, but you'll probably need to install different-length cables if you go back to that location.
Jerry
Last edited by Hotrod Lincoln; 03/01/2014 4:41 PM.