My 64 starting Blues

[jtbart]

Hi everyone. I recently purchased this 64 swb fleetside with a fairly new 350. I wasn't in the market for a truck, but found a guy needing to sell, and convinced my wife by telling her we could make some money on it if we got it for a good price. They guy was wanting $4500 but I offered $1200 cash and a couple of diamond rings and he accepted. I only had $300 in the rings so I was out $1500 total. Felt pretty good at this point. I knew it needed a few things: driver's door latch, ignition lock, steering box, and a few other odds and ends.
And then the fun began. The next day she wouldn't start. I replaced the ignition switch along with the lock cylinder, but it didn't help. My initial thought was the battery, as the truck had been sitting a while I figured the battery may have been weak. But, put a different battery in still nothing. The odd thing is, I'll leave it alone for a day, go out & turn the key to run, the lights, horn, etc. will work for a few seconds, but won't start therafter the accessories won't work. Does the same thing with the other battery.
I'm afraid it's the wiring, but don't know where to start. If anybody has experienced something similar, I'd appreciate any suggestions.
Here are some pics (hopefully I posted right).