I thought I'd update with info about the commonly available (seemingly) military style throttle cables from ebay (as I mentioned previously).
I purchased this one through ebay from a particular seller that said his weret were "improperly stored" but the pix didn't scare me off.
I was pleasantly surprised to receive a really nice piece with some very minor corrosion, but not bad at all. I intend to paint the handle black and refill the embossed letters anyway.
I was worried the shaft size was 1/2", but no, things are even better because it's a 3/8-24 shaft with a flat so it's a direct bolt in to the original dash hole.
It's high quality and features the locking ratchet shaft (same idea as the hand brake shaft) and a quarter turn releases it.
So despite it being not correct, and despite me not really NEEDING a throttle control, I'm going to bolt it into the dash (after I paint it up)
Dave