If you left your code as you posted on here, then follow these directions:
Go into the editor to load your map, select the Tracks & Trips tab, then click on the Edit Timetable... button. From there, you'll see a dropdown menu called AI-Veh.-Group. Use that menu and select "Plain". You must do this for ALL tours on ALL lines. Once you're done, exit out of the timetable and save the map.
With those settings in place, you should see all of the D92s in the Southwestern National livery.
Also, make sure to add 2 lines of space after [end].