This tender was actually put together in 1954 from two ex NYC hudson tenders, by the Toronto Hamilton and Buffalo RR.. When they were phasing out their steam program, they needed a steam generator to heat their coaches, hence the hybrid car.
Joshua Blay, took the photo which was sent to me by David Crosby. As Dave says, "seeing the tender I can picture a Commodore Vanderbilt Clockwork engine with it!"
Could this be the prototype for the Marx 551New York Central rivet detail tender?

(Courtesy of Joshua Blay and David Crosby)