My main throttle linkage and slave throttle linkage doesn't have any play between them. I couldn't locate locate any adjusting screws to reintroduce play between the two. Does anyone have any ideas?

Not quite sure what you are trying to describe!? Why would you want play in your throttle linkage?

In the original 1972 owners manual, it indicates that there should be a certain amount of play between the main throttle linkage attached to the accelerator pedal, and the throttle linkage attached to the carburetors. I believe the reason is to allow the carburetor linkage to make a complete return back to the idle position.

I think what you ask is the fast idle screw.It lives on the balance tube at the top of the short linkage that attaches to your carb throttle shaft.The book calls for 2mm gap.This is really not critical.The screw is used during carb adjustment,not as idle adjuster.As long as its not touching anything when your throttle is at rest,your O.K. Have fun! Daniel

Do you have any words of wisdom in refernce to the balance screw that is located on the carb throttle shaft?

This screw should also have some slack when the car is off or at idle but there is not a diffined measurement. This screw is to balance the front and rear carbs at high speed. Example, when tuning the carbs at idle this screw should be loose so the front a rear carbs act independently of each other. Use a air flow meter to syncronized the carbs at idle. Then bring the engine RPM up to about 2000 RPM and then tighten this screw to syncronize the carbs again. Once you have the carbs sycronized at idle and 2000 RPM you should be good to go.

Hope it helps! Mileage may vary!