OK- - - -I should have enlarged the picture a little- - - - -you've got the right bracket. All you need is the brass sleeve with the anchor screw. Push the throttle cable through the hole in the gas pedal linkage, and attach the stop to the cable far enough below it that it won't interfere with setting the idle speed. Then when you want to increase the engine speed for some reason, just pull the throttle cable knob. Hopefully, the cable sheath will have enough friction to keep the speed steady- - - - -some aftermarket cables don't.
Jerry