Your are correct, but since UP had to "buy" the cars from TTX, its a UP clock now and not a TTX clock. A clock keeps running until the handling carrier gives notice of destruction under AAR Interchange Rule 107 (as provided in AAR Car Hire Rule 7). To stop the clock all the NCRA has to do is give notice of destruction to UP. It is totally unfathonable why NCRA hasn't given, or won't give, the required notice. Car hire could have been stopped years ago.