Rewire Electrical System

I tried to post this question in the alternator thread, but for some reason it disappeared, and perhaps it warrants its own thread.

I am about to do the interior of my 64 Econo, but now I'm concerned that perhaps the 45+ year old wiring should be replaced before I cover a lot of it up. What kind of job am I looking at? Are there wiring harnesses' available (I assume no, but can't hurt to ask). I want to upgrade my alternator and will be having a dual battery set up with a battery isolator. It is my plan to run the stereo and separate amp directly to the back up battery, thereby not putting a strain on the existing wiring. Should I just inspect the heck out of every inch, or will that even tell me anything (other than an obvious place that has had the insulation rubbed or scraped)?

I know enough about electricity to be dangerous, but these vans seem pretty simple so I'm wondering if I should just take it on for the peace of mind aspect. Opinions???

I used a painless 21 circuit system in my 66 Econo. They are easy to install.

It is definitely worth rewiring your van. I recently ripped every single wire out of mine, and was shocked to see just how brittle the wire had gone over the years. It looked ok on first inspection, but once i started pulling it out i came across numerous possible fire starters...!!!

Also, the amount of unfused wires comcerned me as well...!!!

I always make my own looms up. Very simple for a basic system like ours, and is definitely something to consider if you know enough about electrics. It is especially good if you are modifying the system a lot.

I upgraded to an alternator in mine, and will be fitting seperate leisure batteries with some sort of split charger system. I haven't decided how to do this yet as there are lots of options, some more expensive than others. My leisure batteries will be used to power the fridge, tv and lighting inside. Everything else will run off the main battery.

Which battery you use for the amp and stuff depends on whether you plan on using it a lot without the engine running. Also, it would depend on your alternator rating, although most are pretty decent nowadays....