I have a couple of those officiall released film cells from a few years back. I have just left them in their little plastic case. I have three different sets from the E1 VHS release. I just keep those in the box that they came in with the video.
As for film cells to display do you know about the Litho's that have a film cell with them? I have a few of these packed away. Anyways they have the film cell in the frame and there is a little button you can push to light up the cell. When you let go of the button the light goes out. You could rig up a frame with a button so you can light it up when you want to look at the cells.
That is what I would do. I am sure that there are more ways to display them but none of those ideas have come to mind.
Well, I hope that helps.