Have probably shown this before, but what the heck...
...'twas my first 2 rail O scale loco.
Have used it as a test bed for different motors (currently has a Pittman) and was an initial experiment in O scale decals. MEC 671 was an F3, but this F9 runs really well (after replacing the split axle gears, of course...)
Mark in Oregon
My favorite diesel was a American Flyer C. and O. Geep with ringing bell.
Shovel-nosed Burlington Zephyrs.
Any of my K-LineSanta Fe or MOPAC ALCO FA's. Solid, hardy, and easy to maintain.