Originally Posted by SeattleDavid

Yes there are baggage recheck counters straight after customs – the airlines are not labelled but the AA agents are usually the last desk on the left. They can certainly retag a bag when your flight has been cancelled and rebooked, so I would imagine that they can tag a bag that has not yet been tagged through.

Assuming you can get your bag tagged there and put on the belt there, then there is a security right behind the wall (exit from the baggage recheck area, stay indoors and go right down the corridor (it seems unlikely but TSA is at the end and is usually quiet (at 5pm anyway). Take the elevator to the 5th floor and you will be between TBIT and T4 in the airside corridor.