I found this on the Rutland RR site.
<big>A</big>. (01/17/00) The Milton Co-op Creamery in Alburgh,VT on the Rutland used GPEX 544 and 1034, [lettered] "Whiting" for many years. Three cars were assigned to them and made the rounds between Alburgh and Somerville, Mass. I believe the third car was 968(?). In 1960, they started using cars in the pool and the 544 and 1034 went away. I would say that this assignment lasted about 10 years