Thanks, Derrell.
Something happened in the 20's that caused the Standard Gauge engines to be brought into the "Q" fold. If you study photos on the DPL site, you will see that even the big 900 class engines carried the same lettering we are familiar with on the narrow gauge until in the 20's.
You are right that the C&S resisted altering the Narrow Gauge against the Q's control, and the narrow gauge became the "pride" and even "identity" of the old C&S.
We should also point out that it was volunteers from the C&S shops years later who lettered the 60, #71, and Caboose 1006, and they usually used whatever they had in the shops to do the job.
History is a weird thing.