Here is a big fantasy design I've been thinking about. (It's not completely out of this world. I've measured up and it would actually fit in my house but I would have to make some huge sacrifices!)   Givens The givens for me are: It has to be 4mm and OO. It has to be classic period GWR, 1923-1939. I want to see the railway in the landscape. I want to see mainline locos and varied traffic. The last two givens pretty much rule out BLTs because: BLT stations usually fill the model leavin