I used to have Mighty Empires too. I thought the geomorphs it had worked really well (although the cardstock was a little thin - Avalon Hill just spoiled us when it came production quality) and we loved the little models. The rules left a lot to be desired and we were always trying for a long time to write a set of house rules but (as always) never finished them.

I really like what you have done...making good looking connecting mountain geos is going to be a toughie though.