A simple fix is to add a short piece of flat stock like I have circled in the bad picture of my twin W-1 Carters. I needed the throttle to open from the left side of the intake, where the stock linkage pushed up, mine pulls down. Mine is bolted on with a 1/4-20 nut and bolt and allows for adjustment. Mine has the 1/2" x 1/8" flat stock going across center and pulling down thus lifting up on the arm. Yours would be just lifting from a different point. You can always change out the throttle shaft later if you find one, with this modification you can get the truck up a running to see if it's worth the effort.
I found a little better picture.
Joe
I think you're right Joe.
