aftermarket overflows

I just got a killer deal on a 90g tank with two corner overflows, the only problem, the previous owner who is apparently not a smart guy, removed the overflow boxes and covered the bulkheads with acrylic sheets so that he could use the tank for his snakes . Now the question is, where can I find aftermarket overflow boxes? I called AllGlass, Aqueon, GlassCages and Marineland and none of them will sell me the overflow boxes. It's starting to look like I might be building them unless anyone here knows where I might be able to score some overflow boxes.