Ive been interested in this as well. Actually since youve mentioned it i cant bring myself to play because it bothers me quite a bit.

I noticed that in game when you hover over a spot in a region it comes up as "(whatever the city is) Region". All the text files you edited say "(whatever city it is) Province". Perhaps if you could find the one that uses the term region it would be the one you are looking for.

Just a thought though and i havent found such a file yet.