[math-fun] Math belt

I have an old belt that I'd like to replace with a new one of the same design. I call it my "mathematician belt" because it has two tongues instead of just one and they can be fit into a 2-by-38 grid of holes. (One could also call it a person-of-variable-girth belt, but I don't.) Has anyone seen such a belt, or know who makes them? You can see a photo at http://jamespropp.org/belt.jpg . I bought it at Old Navy a decade ago, but nobody there recognizes them, and I haven't been able to find them on the web. Jim Propp