I was trying to make a mine that didnt look so repetitive but ironically I had to add more buildings to add variation, and making use of the green (out of bounds tiles) in the pcx file. If you know the limits it actually works and the extras will duck accordingly. It's not perfect and it has its issues specially with roads but it looks decent for all ages. Here is a sample where you get mines, roads, rails, and farms each added 1 at a time and it blends ok even with the limitations: