Lifting H-O Train platform

We are trying to design a 4’ x 8’ train platform that can lift out of the way when not in use. We would like it to rise to the ceiling of our garage and be able to be lowered to sit on work horses when we want to use it.
Does anyone have any ideas about how to suspend a 4’ x 8’ plywood platorm so that it lowers/rises evenly?

The August, 2003, “O Gauge Railroading” magazine (if I may mention that name) has an article about such a scheme, on page 57.