Lionel #1663 0-4-0 Switcher with #2201T Slope Tender from 1940-42 PreWar production. Three Prong Tender “male” connections to Cab of Loco. Layout Tested, Oiled, Cleaned and Lubed. Since I’m more a PostWar guy, admit this is a bit out of my “wheelhouse”… Not 100% sure about harness hook ups, but all ran well w/ 3 Position E-Unit. Tender backup light did not go on, but probably a bulb or wrong lead from tender. It’s way too Excellent to mess with this classic of which I can find little references..