Don't loose hope! I'd just get the wiring and brakes working.
Since I don't think it's your daily driver, take time and pull the engine harnesses one at a time and rewire them your self. It feels real good when you don't have to worry about shorts and smoking/melting wiring
Get on or go to Harbor freight and buy a package of cheap electrical tape and wrap it all up nice. (on my '64 the starting harness wasn't that bad at all, and i HATE wiring) Next it to get a pertronix set-up for the distributor, check timing and vacuum of the distributor, run some diesel fuel in the motor oil and let it just idle at about 850-900. (its cheaper than Marvel mystery oil) and run a couple of old cheap oil filters on it like that until you feel like it runs a bit better, Then put some Shell Rotella 15w40 diesel motor oil just a bit over full. The diesel motor oil has a higher TBN rating to give more protection of the oil breaking down.

This is what happened to me more than a few times.
Pick up a vehicle that owner says "it's just sat about a year!"
You put in about 5-10gal of fresh gas, and it might run fine for a day or two. Then the fresh gas dissolves the varnish in the tank and turns all the fresh gas into crappy, sticky, smelly gas that coats the intake valves, piston heads and eventually behind the rings. I pulled one motor apart that supposedly 'ran' and it looked like someone painted the pistons and intake ports with GLOSS black paint..
I just bought three older vehicles and actually ran Amsoil 2-cycle mix in two of them just to lube the fuel system and in the 3rd, i mixed 3gal of diesel fuel with about 7gal of gas (just because I knew the owner and believed him on how long he said it sat) It smokes a little but hasn't seized the valves in the guides!
OH and don't forget to check the cooling system. I usually drill a few 1/8" holes in the thermostat so if it sticks, at least SOME water will be moving around and helps 'burp' the system too.
Calcium and rust have slowly settled in the bottom of the cylinders and radiator tubes, and once you know it won't freeze in your area, flush it and flush it again. To do it right it takes almost a whole day. drain, fill with flush, run til warm/hot, let cool to the touch, drain that, fill again with clean water, run til hot/warm, let cool again, drain, fill with water again and this time add more flush and (I like to let it sit over night) run it til hot, cool, drain by taking off lower rad hose for any large sediment to flow out, and finally give about 1.5-2gal of anti-freeze then the rest with clean water (distilled water if you can). There are 'anodes' that you can hang down in the radiator/coolant for motors that sit for long periods of time that help with corrosion.

NOW, sometimes you run the risk of cleaning corrosion out so well that some might be plugging a leak, so be prepared to find leaks if that's the case. (you never know what the backside of the pump/impeller looks like either) It might have a blade or two that are rusted/corroded off and not circulating much at all.

Next, I'd find some "Kroil" rust penetrant, and spray it on all your brake line junctions and connections. This is fantastic stuff! Just EXPENSIVE.. you only need a little every few days or so to let it creep in frozen/rusted stuff.

My '64's brake parts aren't cooperating whatsoever and might need heat. Once you brake a bleeder off or snap a line because it turned with the wrench, 'yer screwed' as they say down here..

Your truck looks really nice. I'd scuff off the scale with some scotch-brite/soapy water, clear coat it, and GO.
Keep that aged 'patina' look.

I usually have several projects going on at once, and when one get's me mad I just go to another and so on. It takes alot out of you by being frustrated and angry at one thing all the time.
That's how 'projects' usually get sold.. As basket cases.

Gotta run. Errol