DADS50,
I like your setup using the original knob. I too do not like the look of the aftermarket relacement. They make a plastic chrome one that is suposed to "look like the original" but is very cheesey looking.
Where did you get that drive cable?
I did have to use a reproduction knob.
The original knob is pressed onto a barbed shaft.
..pic.. I drilled and tapped the repo knob for a 6/32 set screw.
The cable fit inside the original escusion and I filed a flat for the set screw.
...pic.. The other end of the cable fit over the shaft of the modern Newport switch shaft.
...pic... I dont know where the cable was ordered from. It was a spare from mechanic I know.
I can only guess its a flexable shaft for a rotary tool or something like that.
its 3/16 diameter and 16 inches long.
Good Luck