Built in 1929 at the Milwaukee Road shops in Milwaukee, this caboose was originally numbered MILW 01612 as part of an order for 15 drovers cars, the first steel cupola cabooses built by the Milwaukee. It was rebuilt in the 70's, first as an instruction car and then as an office car, and was renumbered X-5001. As the Lines West Superintendent's car, X-5001 traveled the electrified divisions of the Milwaukee's Pacific Extension between Montana and the West Coast. Milwaukee's 1977 bankruptcy and abandonment of the Lines West brought X-5001 back East by 1980. When the Soo Line acquired the Milwaukee Road in 1986, they repainted it red but kept it as an office car and retained the X-5001 number. In 2001 the Milwaukee Road Historical Assoc. acquired X-5001 from the Canadian Pacific Railway and donated it to the Illinois Railway Museum.