Currently townhalls have the same face for the same city size regardless of age when it was built. So I have following idea for townhalls:
I think that townhall built in city of fifteen thousand people in year (for example) 1910 should be different from townhall built in city of fifteen thousand people in year (for example) 1948 or 2000.
pak64 has an old style townhall for low levels ...
So, it's a pak-dependent issue.
So, if someone wants to paint them, the code is ready for it!