Every now and again Tracy gives me one of these...
This one is a windmill
Here are the others. They are about right for 25mm, I made each roof removable and added a floor to the flat-style building in the middle
She gave this to me about five minutes ago :) More like 1/87. I might make templates from any future ones and modify them a bit more to suit needs. These are from China and are between AUD$4-6 each, often with free postage.