74 Duster (318) ignition not working, not getting spark

Holy **** that's some cobbled up wiring. Did you unplug the bulkhead connector from the firewall and clean that up? I do it every spring on my Mopars with just terminal cleaning spray and the spray protectant you can get over the shelf. If it's never been done you might be surprised what you find.

But seriously, just spend some money and buy a new engine harness and battery cables. Anything is better than what you got now.