Richard,
The only thing I'm certain about is that the cab roof was black.
I've never given this a grain of thought until yesterday. I'd be surprised to learn that the shop crew had time to do that at the end with all their time spent trying to keep that old stable of engines running.
I guess I'd try to see if there is any indication that any of the other engines might have had raised numbers like that.
Remember that going back years, certain engines were assigned to certain Engineers. In later years, the most senior Engineer on the West End, who held down the Passenger run to Leadville, was Curly Culligan. Maybe he had them made. #9 was his pet.