As most of you guys know, I have a dozen or so complete or partial DOE wrench sets. Sone of them are in holders. Vlchek, Barcalo, BHM, and a couple others. A good many of them are not though, especially the sets like Kraeuter, Southington, ETF, Lakeside and so many others that I am building onesy-twosy. They're space hogs, difficult to stack, and problematic to handle and move around loose.
I am experimenting with some ideas.
I kind of like the C clamps. They're mechanically fitting, vintage, fairly prolific and cheap at fleas, and they actually work very well.
On the right is a modern generic no-name holder that is supposed to stand up that I have adapted, turned upside down, and laid flat.