David,
My initial thought was the crown was a Russian Baron's crown, but that has six, not five pearls. I agree that the M and crown are excellent work, and the train itself is charming. The words in question are scratched in the surface, but not colored in like the rest. It also looks like someone tried to scrape the words out afterwards. Am beginning to suspect that some child got a hold of the box and tried to engrave something under the "M" as a prank.
Nonetheless, I just fell in love with the railroad scene. Never saw anything quite like it before.
Rob