I think you have the wrong era, and the wrong riot. The lack of ammo incident involving the NG, occurred in '92.
I didn't care about the 92 riots because that's the year I closed the construction company and wouldn't be involved plus all my friends in law envorcement had retired by then but as far as Watts the guard was riding around in jeeps with machine guns with no ammo, the Sheriffs dept was the one that did the most to restore order.