No, harnesses on Military trucks from the 40s were braided with black thread with tracers.
http://www.tm9-801.com/searchTM9/tm9_pages/325.pdfLater on some MVs did move from braiding to vinyl type tape.
Yes, braided wires are available. Simply search 'braided wire' and lots of places will come up. Typically $0.15-$0.50/ft.
I have found several places that will braid for $5/ft or so. Not bad.
I got my Chevvy G506 harness from 'the leader in MV harnesses'. That's as close as I can say. I do plan on documenting the issues on my web site, simply due to the amount of photo's required.