Probably the most interesting thing I've scratchbuilt was a little miner's cabin based on one in a book on Appalachian coal mining, in a VGN company town. Dimensions were guestimated and the four walls cut from a single piece of cardstock. Board n batten siding look was created with strips of scale lumber. After I finished it I realized I had gotten the pitch of the roof wrong, but no worries, it still looks just fine IMO. I 'finished' it 7 or 8 years ago, I guess, and had it boxed away until recently. Now it's going to find a new home on my timesaver switching layout as a section house for the track gang. Needs a few legs to raise it off the ground and perhaps a few additional touches. It's too late now but I'll try to get a picture up this weekend.