Only recorded A-4 Mig kill of the Vietnam war occurred 1MAY67 by LCDR T.R. Swartz flying an A-4C from VA-76 off the USS Bon Homme Richard. Occurred while attacking an airfield with Zunis. Wingman radioed bogies at his six, he high-g-barrel-rolled to their six and launched several Zunis at the Migs. Wingman confirmed the kill.
Only one I know of. Don't know about the Israelis.
I think that had somebody wanted to keep extending the life of the airframe, the A-4 could still be extremely lethal. Think of it with a non A/B F404, ( I know...probably way too much motor)...and a few AIM-9X's slung under the wings.