The initial Pilot's Operating Handbook for the XP-51J shows 2 pylons, cleared for 100-500# bombs, or 75 U.S. gallon drop tanks.
Bomb controls are the stick button, electrical safe/arm, nose fuse, and tail fuze switches on the control panel, and a mechanical Emergency Jettison handle on the cockpit floor. It doesn't say if the bombs drop as singles, or a pair (I'm inclined to say pair).
The Emergency Jettison drops the pylons and, of course, whatever is hanging from them at the time.
Nothing about rockets, or any rocket controls.