I'm cross-eyed from looking -- but I still can't find the Rules Book statement of where to enforce a loose-ball play foul that occurs beyond the line of scrimmage.
I know that these fouls (by A or B) will be enforced from the previous spot. But, what is the specific rule reference that states the enforcement spot?

Post scrimmage kick fouls are covered and lots of statements re running plays. But I don't find that specific loose-ball play foul enforcement spot.