Here is a final assembled support cable.
I used heat shrink to cover the ends of vacuum hose that I had pushed the steel cable through.
I also used some heat shrink on the loop end that will anchor loosely to the bed side using a spare fender screw. (since I am raising the bed deck, there was no need to use these fancy screws where they would not be seen which gave me enough to use on the bed head board as well)
Here is it supporting the tail gate as I ensure the tailgate is hanging square to the bed:
Yep, pretty much nailed it:
And just as a follow up, this is what the rear fender side marker/turn signal lamps ended up looking like:
Man, you just have to appreciate the fact that you are dealing with auto body parts that are almost 50 years old, when once you lay paint on them, EVERY battle scar becomes visible !!
And a final shot of the bed sides on, and the fenders hung with power to the light (I am using an ATV battery to check electrical continuity and illuminate the lamp):
All in all it was a good weekend, a lot was accomplished !!!
I suppose it would look more like a truck if it wasnt draped with dust cloths....
Thanks for looking and all your support guys, you all make sharing this adventure completely worth while !!