Brother Poteet
IIRC, the Pacemaker was a high speed, extra-tariff merchandise service, featuring the NYC's first roller bearing cars. It operated that way (Pacemaker scheme boxes in dedicated service) for a while, then faded away. The Pacemaker scheme faded away more slowly as the cars were repainted. Some of them might even have been patched PC - but I can't prove it.
Chuck (modeling Central Japan in September, 1964 - previously a NYC fan)