Simple storage box for rolling stock

I wanted to keep my growing collection of rolling stock safe when not in use, and protected when in transit. I designed a simple box made of 4mm plywood which would take two 4 wheel coaches / wagons or a single bogie coach. The sides, top and bottom are all 160mm by 480mm, and the ends are 160mm by 152mm.
The sides, top, bottom and one end were assembled with PVA adhesive. Two plywood stips were stuck on the floor 32mm apart to act as guides for the wheels. Pieces of soft foam were stuck on the roof and rear end to protect the contents.
These were chosen so that the coaches can be easily slip in and out, yet remain secure once inside. In this picture, the box is actually standing on its end, and the coaches do not move. The remaining end is a tight fit, and remains firmly in place for transit.