Below is some information on the Boston & Maine Caboose at the Raymond Historical Society. This information is from the Publication entitled Boston & Maine Caboose (By Tim Gilbert) 2nd edition.
This type was a Penn RR design and was the 1st all steel design. The Pennz RR owned a piece of B&M after the depression in the early 1930's. The parts were probably purchased by PennZ supplier’s and were assembled in Concord, NH!