I had to put up a sort of back stop, felt track way to close to edge and i needed elevation and can not have elevation with a drop off, consequently i added plywood to the three sides in the back, a continuation of what is seen so far, My plan is to (once all terrain set and track down) to cut off excess ply and roll over the edge with one of the various paper mache available, probably plaster of paris type.. the cut would be higher than the ground elevation but not so high train could go flying?
not crazy about my skills at the painting of a Muriel or a sky scene this aint in the cards,
i also used this method to make tables a bit wider, added 1X2" and then plywood over that to make the board somewhat bigger also to prevent accidents.
so in review my idea is to (once all terrain down) trim off the excess ply board
comments. I am sure open to them, the upper left corner i really do not like with plywood around it it makes it look like a kids sandbox and that was not the plan