Hi Young Al
Below is a plywood carry case based on one I saw at an exhibition, There is room for two engines or carriages side by side when it is closed for transport. They sit on rails built into the case. Or if it is being used as a display case one can be shifted to the top. There is also a drawer. I guess you can make the case as long as you are able to lift it. It is probably an old idea but it worked well.
You would need to make restraining packers and or hold down straps to hold them in position for transport.It would need handles and catches on the sides and a piano hinge for the top. A handle on top would need to be recessed or it would get in the way when the case is open.
I guess you have noticed I am not a train builder!…. I do not have an accurate 3d image of a real engine so just sketched up a kids version. It was fun!
Regards
John

Edited By John McNamara on 10/12/2013 13:06:24