The last seven minutes or so of the film show the Besler steam car and trailer that were purchased by the New Haven Railroad. This train typically ran between Waterbury and Bridgeport, CT, where the branch line passengers would connect with Shore line trains. The train set was not considered a success on the New Haven for a number of reasons, including 1) the cars chosen for conversion were a pair of old New Haven heavyweight coaches -- far too heavy for the Besler power plant; and 2) as Ken noted, the trainset was not popular with crews, since the trainset was much lighter than the regular trains operated by Pacifics, and the crews' rate of pay was typically based in part on the weight of the train. By 1943 this trainset was off the roster.
Information is by A.M. Bixby, Sr., one of the senior mechanical engineers of the New Haven Railroad, who was involved in the purchase and maintenance of this train set, as he wrote in the Vol. 14 Issue 1 1983 issue of the NHRHTA Shoreliner magazine.