A baseboard idea

As you know I'm no woodworker. I'll go to all kinds of lengths to avoid using wood for model railway baseboards. Pink foam, cardboard boxes even storage boxes from IKEA. All to avoid putting a saw to wood. 

Three or four years ago I was presenting a series of workshops at the local model railway club on Micro model railway layout design and construction and as an experiment I made a baseboard up using 3/4" expanded polystyrene foam for the surface and framing with a cork surface to lay the track onto all glued together with foamboard adhesive. The other day whilst looking for some tools to work on my MGB I re-discovered the baseboard and took a fresh look at it...

This is what I found after 4 years of being baked in close to 100 degree heat in the summers and -30 degree chills in the winters. Still flat and square and level. A sturdy and very, very lightweight baseboard. I think this method can be used on the new layout. I have plenty of the styrene sheet in hand too. Some 4" x 14 1/2" sheets. Which as you will know from the previous post is pretty close to the size of the proposed layout.
Everything is just falling into place, isn't it?