Re: push pull pot grounding
Assuming you're using it as a volume pot, just connect the ground wires to lug 1 of the pot, the one that would normally bend to the back of the pot or use the back of another pot. Or better yet, get a small washer, connect all the ground wires to it, then connect the washer to lug 1 of the push/pull pot. You should shield the cavity with shielding tape or heavy duty aluminum foil so that all your pots are connected without the need for ground wires connecting them, much like what a Tele control plate does.