@Ross posted:John,
I have a couple return loops with O-31 track on them. I just tried one of my Williams Amfleet cars around it with no problem. For a Genesis engine, timeline wise Phase 3 paint (3 equal width red, white and blue strips) or Phase 4 (narrow red and white stripes over wide blue stripe) paint would work.
Thanks, Ross.
Found some Williams Phase III passenger cars at Western Depot. Look pretty decent.
Item #43501.
Not pulling the trigger yet, but will put them on my list of possibilities.