If it ran that low on oil, I'd sure be looking at my cam journals if I were you.
Even a "low" oil level was always an issue for the 200X and 350X and a seized cam makes it very tough for the engine to turn freely.
If it has BALLS from 0 to 1/2RPM I would also be looking at the carb but unless stuff got plugged (your filter did fall off partially) I can unly see the needle clip falling out and it's done it to me.........
BALLS without a load are different from BALLS under a load........
Thatt filter let some crap in so entirely disassemble the carb and clean out every orifice and jet.
All our government does is distract us while they steal from us, misspend our tax $ and ruin our country