I gave up on trying to find decent display cases and went with ballistic nylon padded cases made for me by Hafner's in Florida. They do a great job and will make them to any specification you like. I have a couple for folders and pocket knives up to 4" in length, that will hold up to 44 knives each. I have several singles for my Randalls, one Corby and a Bauchop, several quads that hold 4 knives each, and larger cases that hold up to 12 fixed blades each.
He can make them in any one of a dozen colors and styles and they are extremely well made. He can also add external pockets and other touches. He even makes a new one designed to hold the entire fixed blade and sheath.
For now that works for me, and the only knives I have in larger display cases are my khuks and swords. Still, I would like to find a couple like yours to show off some nicer stuff.
Norm