From my readings, NYC did run an overnight LCL service between New York and Buffalo beginning in 1935-36, but not with the "Pacemaker" name. That dedicated LCL service was discontinued during WWII. When NY-Buffalo LCL service resumed in 1946, equipment for that service received the "Pacemaker" logo and red (vermillion) and gray colors. (A similar LCL "Pacemaker" service on the B&A between Boston and Buffalo began began in 1948-49, at which time the NY-Buffalo service also extended to Cleveland.)
The NYC "Pacemaker" boxcars were 1945-Despatch-built equipment delivered in BCR. When selected for "Pacemaker" service beginning in 1946, they were downrated from 110,000 to 50,000 lbs CAPY, had high-speed trucks installed and brake equipment modified, and were repainted; in contrast, the 25 1954-built PS-1s were delivered in red and gray. Many, if not most, had limited data stenciling to restrict them from interchange (see, for example, (<http://www.canadasouthern.com/caso/images/nyc-174131.jpg>), or had a large star stencil (i.e., larger than often seen adjacent to weight stencils) below the NYC emblem or elsewhere on the sides (see, for example, <http://www.canadasouthern.com/caso/images/nyc-175000.jpg>), apparently to designate the same restriction. After the "Pacemaker" service was dropped in 1957 (or 58?), the cars were restenciled for general service and could be seen offline in red and gray (see, for example, NYC175431 XM with a 6-60 reweigh stencil at <http://www.canadasouthern.com/caso/images/nyc-175431.jpg>, note also the lot number "737-B" above emblem, and the fairly new weight data and car number stencils compared with the weathering elsewhere).
My guess is that the C-D-S info merely reflects the imprecision in their sources, a misdemeanor at worst and not atypical for large suppliers of decals/dry transfers.