A UP Challenger arrived in Illinois ...prior to the one coming from Cheyenne...this one scratch built by Jesse Bennett of Idaho in S Gauge 3/16" scale ..1960's -70's ...Jesse built a number of engines for his Great Northern Pacific RR ...several Challengers etc. This one has an open frame Pittman motor in the tender .
Please see link for video of engine running .
https://youtu.be/rFIJrXk02VE
Cheers Carey