If I can get to my car, I'll post a picture later....
But....having "been there, done that"...I did a little searching, and found something that might help......
Try Desert Valley Auto Parts in Arizona. They have a website that you can search for parts from all kind of cars.....which mostly look original.....
Get into their search engine, and do a search for all Chevrolet's in the yard.....I did, and there are plenty of 69 Impalas, which surely have the 350ci with TB350 trans combo.
You just have to be specific in what you ask for.....you need: 1) the holding / adjustment bracket off the rear two drivers-side intake manifold bolts, and 2) the cable which should be attached to the carb & trans.
The cable that you see near the carb / engine should look like a slot with a bolt that goes through the cable slot and tightens against the bracket attached to the engine.
I think this place may be your best shot.
Good luck and let us know if you scored or not.........I gotta good feeling about this.