Why don't you just make one? Got a router? Centuri cabs are the easiest to duplicate because they bolt together. If you just need the sides, take it apart and rout two new sides using the better old one as your template/guide. Mark and drill the bolt holes and cut your t-molding slot, and presto! Then put 'er all back together.
I'm fiddna make a new Centipede cabinet by doing the same thing, but since I like the shape of the Asteroids Deluxe cabinet and the Centipede is almost exactly the same, I am going to make the sides the same as the AD. And it will be made of BIRCH and NOT particleboard!!