Bulkhead wire 64 Barracuda

I'm not familiar with the 64 either. I would replace the fuse wire with one continuous lead from each side of the fuse. You should also be able to disconnect the bulkhead connectors and clean up the terminals. Many folks replace the terminals with new Packard 56 terminals. I just cleaned both sides of mine with a small file and packed it with dielectric grease. I kept my amp gauge but did the fleet bypass. Again, not sure how the 64 is wired.