Unfortunately that is not much better than regular 300 ohm twinlead 0 in fact that is what it is.
I think he is looking for the type with about 3 inch seperation with standoff about every 12-18 inches.
My reading seems to indicate most of it was "home made".
Very low loss for long distance transmission of TV signals, used in the 50's for rhombic antennas in open areas where the antenna was a 15 X 30 ft rhombus mounted on telephone poles 20ft or so off the ground - talk about DXing - but the rotator is a killer!