After more than a year of planning, evaluating, ripping up all the plans and starting again the baseboards for the layout are in place.
In the end the layout had to be reduced in size as I wanted to keep one end of the loft free as my workspace for my modelling projects. Also the space down the two long sides of the loft is just too limited for it be practical for track runs.
What I have is a rectangular set up with a central operating well accessed by a duck under. The two long sides are 10’ x 2’ and the short sides are 7’ x 3’. I got a joiner friend of mine to make them to an open frame design.