( searched for "accelerator pump lever" and "roll pin" and got no hits.)
Played with a '77 Chevy 350 pickup Q-Jet yesterday. My friend "rebuilt" it. That is, he fumble-fingered the thing til I couldn't stand it any more, then I put it back together with new gaskets.
Something I don't remember from other Q-Jets: The accelerator pump lever pivots on a tiny little roll-pin. The airhorn casting did not have a hole drilled all the way through for the pin to fit into. I usually just smack the pin with a thin punch, push it through towards the choke tower to free the pump lever, and therefore the linkage down to the throttle body.
Since this casting didn't have a through-hole, we had to leave the lever in place. Made things more difficult.
HOW would you ever get that roll-pin out? I don't like the idea of drilling a steel roll pin shoved into a soft-metal casting.