It's not that difficult as to geometry (sorry, I can't tell you the exact pieces).
1. find the length of travel the 700R4 cable makes between idle and WOT.
2. is there a part of the existing linkage that moves that far (sometimes an existing arm can simply be extended)?
2a. if yes, does it go the right way (push or pull)?
2b. if no, try to find a linkage point (hole, bushing, stud) that is easy to reach, away from the carb and manifold as much as possible. Measure the travel the same way.
3. compare the distances - this is your leverage ratio. Example: the 700 moves 4", the throttle moves 3". You need a lever in the same plane as the carb shaft that with 2 link positions (holes, studs) in that ratio: 4:3 (the arm operating the 700 must move faster than the link from the carb). Use Heim joints or ball/sockets rather than "L" shaped ends or clevises, and allow some adjustment for length in more than 1 place.
If the useful carb bits move the wrong way, the link should be a bell-crank with opposing arms to reverse the 700 motion, etc.
Sometimes you just can't get the lengths right, and the trans cable moves too far. In this case, use a small spring and some slack distance.
4. return spring operates at 90° to the link
