You can buy the proper mil spec wire, the connectors, and the crimpers. I recommend the C24 pressure tool crimpers by Buchannan. If you go to your local electrical supply store they will run you about $60, however if you watch ebay they can usually be had for about $20 or so.
http://www.ebay.com/itm/BUCHANAN-C-2...item564e0f3b69
For the connections, you can get away with buying just the terminals and the rubber grommets, and re-use all the metal shells and the insulator. Avoid the temptation to use commercial automotive wire....the vinyl will not look or last as good as the rubber coated mil spec (usually made by prestolite) wire. Also, you are best off to solder and crimp the terminals. If you can find any old deuces or M37s in your neck of the woods, they are a good source for salvaging the shells and insulators. Usually the ones found under the dash are pretty minty.
I note that lately the prices on the connections has been bordering on ridiculous. When all is said and done, you will be a lot cheaper off buying the harness from one of the dealers. I wouldn't bother with a salvaged original harness. They will be 60 years old, and while the rubber coating on the mil spec wire is good, it isn't that good.