Identification Help

So I got this lovely little lady at the Goodwill Outlet Center, last stop before the landfill. They only charged me 9 cents. After peeling out the corroded batteries and cleaning her up some she runs loud and strong. Can anyone tell me more about her? She was obviously tethered to something else, possibly Thomas? There are broken wires hanging from the coupler. There is an on/off switch on the bottom which I assume activated something on the missing unit.