VO-1000 No. 67729 emerged from the Baldwin Locomotive Works Eddystone, Pennsylvania, facility in July 1943 dressed in the Santa Fe "Zebra Stripe" livery and bearing #2220. In the early 1960s the unit would take on the blue and yellow "Billboard" paint scheme with "SANTA FE" displayed in small yellow letters above the accent stripe, as was the standard for all yard switchers. It is these colors that #2220 displayed when it was selected as a test subject. Much as with the CF7 conversions, the unit was stripped down to its bare frame, and the long hood, power plant, trucks, control gear, and electrical system scrapped; only the Baldwin cab remained.