Well, after some time running trains inside I came to the conclusion that for O gauge the room really was very limiting and to be honest I have never been a fan of having trains loop around behind me. I much prefer the punter's view at an exhibition.
So after another dice with an O gauge shunting idea I reverted to a central loop idea.
Once again I could have gone to S scale but thoughts of having to scratchbuild in two scales didn't appeal at this moment so it had to be go find what HO was still lying about.
Here is the result with temporary scenic items scattered about.
It is, just a means of replicating inside, the train watching I do outdoors when the conditions are not suitable.
Much more can be found on my threads on Freerails.