Intriguing for at least a couple reasons, Lionel's 1985 Collector Series Burlington Northern Limited included an SD-40 diesel, five box cars and an extended vision caboose. Of interest and note is the inclusion of the Standard O tooling for the BN box cars and Lionel's unit train consist of the same green car with five different roadnumbers. Lionel tended to exist in its own universe and such concepts as a set of cars from the same road with different roadnumbers seems to me to be getting dangerously close to world of serious rivet counting model railroading from the toy train land that Lionel usually called home. The set was sold as separate release or a buyer could purchase the Burlington Northern Limited (No. 6-1552) as a set.