I have decided that my narrow gauge will run from behind houses at the back of the layout, through the town and on to the front right corner, running over one of the storage sidings which will become a hidden siding.
For Christmas I rquested a 009 locomotive kit and a chassis to fit it on, and I now have to construct and paint the kit, add the backscene on the layout and modify it to take the narrow gauge track. That will keep me busy for a while.