Bret,
I have some older photos of the turtlebacks, and a few of them have low numbers. Two of the combines were #10 and 11, if that helps to clear anything up. Also, for some reason I think I heard somewhere that all the coaches and such were numbered starting at 20, but all the baggage, RPO, and combines were numbered 1-19. Of course, when the passenger fleet started to dwindle, cars were renumbered, like combine #25.
Talk to You Soon, Taylor