Welcome Kris Dales: So you are as crazy as me and jumped into this vintage Airstream hobby, the deep end it sounds. Rewiring an Airstream with the interior skins off is certainly do-able. You've got to study it some and you'll be fine. Here is Airsteam electrical 101 to get you started.
1. Airstream rather invented the "univolt" trailer electrical system. The idea is to have all the trailer's systems run on 12 volts. Furnace, water pump, roof vents, lighting, and the like. Doing that, you can park your trailer in the middle of a field and have all the comforts the trailer offers.
2. The 12v
battery (direct current, or DC) sits at the head of the table for your electrical system. Direct current has a "positive" and a "negative" terminal at the battery. All your trailer's systems are wired to the battery. Many trailers have two batteries for extra power and life before discharge. The batteries are "deep cycle" batteries designed for many charge, discharge cycles. They are not car starting batteries.
3. So now you have to charge your batteries. The battery power only lasts a few nights before the batteries need charging. Your electrical system will need a "converter" that converts 115vAC to 12VDC. The converter is powered by 115vAC. Heck, since you are charging your batteries, why not run all the trailer's 12v
items off the converter while it's plugged in? Saves wear and tear on the batteries.
4 Since you have to plug in your trailer to charge the batteries, why not run a 115vAC wire to an outlet so you can plug in a microwave? Or a electric heater, or or a TV, or an air conditioner? So your trailer will have 115vAC wiring to power outlets and the AC.
5. Most Airstreams run on 115vAC with 30 amps of power. This is about 3000 watts of power.
6. You have to protect your 12v
circuits with fuses. And you protect your 115vAC circuits with circuit breakers like your house might have. So you need a fuse panel for the 12v circuits, and a "power distribution panel" for the 115vAC circuits. My old 1966
Airstream Trade Wind has 3 12vDC circuits protected by 15 amp fuses, and 4 115vAC circuits protected by 20 amp breakers. I have a separate wire for the microwave, and a separate wire for the air conditioner. These appliances pull significant power and shouldn't be running if something else is running.
7. Now you need an electrical plan. Yes I want an AC, yes I want a microwave, yes I want two outlets in the bath, yes I want a 12vDC charge port for my phone and tablet, etc, etc. Figure out what you want and where.
8. Also figure out where you want the batteries so you can get at them for maintenance. And figure out where you want to have the "outlet" where you can connect to 30 amps at the campground. Most electrical shore power connections are on the left (street) side rear.
RV wiring is a bit different than house wiring. The things you will need to buy are batteries, a converter, a fuse panel, and a power distribution panel.
And first things first, you must get in your trailer and identify every wire that is left. What did this wire do? The label them; e.g. 115v wire for bedroom outlet, 115v wire for air conditioner, 12v wire for furnace, 12v wire for fridge, etc.
Here is a wiring diagram for my 66 Trade Wind. At least it shows the basics. You can find a wiring diagram for your trailer on the internet somewhere.
And here is a photo of my fuse box, my converter, and my 115vAC power distribution panel.
I hope this little post helps you with the basics and helps you begin to sort things out.