Thanks - it's HO - all just normal Proto/Trix/Atlas stuff with some weathering and the odd additional bit added. Attached is a recent pic of my Challenger too.
Brian
My UP interests are in the 1950s - attached are a few pictures of most of my UP locomotive fleet. All are sound-equipped, and the 2 ABBA Alco sets tend to raise the roof a bit when they power up:
Brian