Jay, when I use to work the card shows I had turntable display cases that I had set up on my tables along with 2 standard lay down cases with a plexiglass lid. The turntable type are the ones you see on jewelry counters that they use to display watches and small ornments. I purchased these from different dept. stores before they threw them out.
The turntable type I use to cut white cardboard the height of the case and insert it inside for a backdrop and support so I could stand the cards up in a top loader for viewing. These display cases you could lock the doors so no one but your self could open them to get a card for a closer look. The lay down cases were 4'x3' in size with 1"x3" walls, the bottom was made from panel board with a piece of felt glued on the inside. The plexiglass was drilled and hinged on one end and 2 plastic type twist locks on the other end that would secure the glass in place and also act as a security lock, these would be mounted on the end of the case where you are standing and also I had a handle mounted on this end in the middle of the 3" wall for carrying the case from the car to the table. I hope this information will be of some help.
