[Arran]

Ron;
  I found this one that same site you linked to, it's not the same as the original Philco stuff but at least it looks like it's from the era, asphalt wire loom:

https://enginebarn.myshopify.com/collect...e-loom-1-2

I've heard of people striping out bungie cords and some types of rope to get an old cloth style looking loom but this might be better. Of course there is the ready made cables that AES sells, they used to call it Atwater Kent power cable, but it probably has wires of the wrong gauge for thinks like the 690s.
Also thanks for that link, I don't think that they are really and antique car restoration supplier, I think that they are more for the stationary engine restoring crowd, though you could use their materials and parts on really antique cars too, or 1920s battery radios for that matter. I like the fact that they also have cloth wire with tracers much like the stuff the original 690 cable has, that's a little more difficult to find then the plain coloured stuff.
Regards
Arran