Well a conversation with my wife led to agreement that the railway will move rooms. That led to me deciding to build the second baseboard, which led to me thinking about how the new room would affect design, which led to some design changes. Then I decided if I was going to be in a new room, but only for a couple of years that we will be living in this house, I really need to make the whole thing properly portable. So the new baseboard was built, legs added to the whole thing, and bolted to the old one.

First up, the new baseboard in the new room, albeit not the final location yet. Pool table to go first...

And secondly the new design...

Purple will be hidden / fiddle yard. On the right will become goods, not yet designed. The two main boards are now built, time to get into track-laying again.