I'm a little confused here....nothing new, but it appears the "throttle cable" , or the choke cable, is used by hand as the gas peddle?
If your gas peddle rod is hooked to the linkage/swivel on the side of the engine, and then goes up to the carb, you should take out the wire we see and in lieu of the clip your looking for you can use a washer and a cotter pin to tighten it up until you can find the pin. Then hook the cable back to where it belongs, either the choke or as a throttle cable. There is no cable like in the pic that is part of the gas pedal to carb linkage.
In reality the throttle cable is used to hold the carb linkage in a certain spot once you get the speed where you want it.......sort of like a cruise control.
Hope this makes sense to you.