Hi Chris
I think its the original paint, but I’m not sure. There’s no overspray on the model and other plaques, but it just seems to good to be true that it could look like that after 86 years! And there’s no sign of any decal on the miller cover, suggesting it might have been painted over, but then again I don’t know if it had one like the 56 does. I agree with you, I like them to look as they were at the end of their real working days rather than being restored, and you don’t have to feel bad about using them for working events as there’s no new paint to worry about marking!