The main station board is big, and unlike every other board so far, is supported by a semi-free standing table. This table is like the rest of the layout is of L-girder construction.
One of the things I worried about in the room is what flooring to use. Normally a hard floor would be better for several reasons - less fluff to get in the works, and much easier to keep everything level. But we live in one of the coldest parts of the country and I just couldn't face a cold hard floor! To try and keep levels constant on a carpet I have cut large plywood feet for each of the legs on the table.
This isn't a problem for the rest of the layout as it is supported on brackets mounted to wall so doesn't care what level the carpet is!
I have used DCC concepts alignment dowels to match up the North approach board woodwork to the table that the station is going to stand on.