Western Pacific's "covered wagon" fleet included equal numbers of "A" cab control units and "B" cabless booster units, and the cabless locomotives illustrated the diesel "building block" approach in which extra units could be added and controlled from a single cab to power large trains beyond the capability of the biggest steam locomotives. As locomotives aged and were traded for newer, higher-horsepower models, the less versatile "B" units were often retired first because railroads preferred cabs on every locomotive for use in any service. By the time the FRRS established the Western Pacific Railroad Museum, all of Western Pacific's "B" units were gone or beyond salvage, but the collection still sought one to represent the type. In the late 1980s, after some Canadian National Railway "B" units had been sold for scrap, one operating unit built in June 1951 as CN 9039 by General Motors Diesel Division-Canada was purchased and restored to represent a Western Pacific freight "B" unit. It was repainted in Western Pacific's classic orange and silver "Zephyr" scheme, assigned a fictitious Western Pacific number based on the railroad's numbering system, and today is maintained in mainline-ready condition. The locomotive is an upgraded F7B rated at 1750 horsepower, with serial number A-214, an approximate original cost of $168,000.00 U.S., a top speed of 65 MPH in Western Pacific service, and an operating weight of 249,000 pounds.