Very nice! I am planning to re-do my original cage base (the 2x4 side) with storage underneath, exactly the way you have done there. Excellent design, and very clever use of the old cage. I'm sure your piggy is very happy in his new abode!
Actually, we don’t use THAT much bedding. Our piggies really enjoyed jumping over the lip. We’ve moved recently, though, so we rebuilt the caviary—a little bit bigger, this time—without the store-bought cage. I need to get some pics of the new one on here!