Debbie - my Dad made a few modifications. He made the legs of the perches a little taller and then cut a U shape into the top of them so the sono tube would fit better and sturdier. He also made the shelf removeable. It sits on supports. That makes covering it much easier - I think that is a change, not sure. Also, we made the lowest perch the tunnel instead of a half perch and that is Jazz's favorite spot!

Can't wait to see what Dennis makes - he's such a good craftsman!!!