Hmm. On the one hand, I think it's pretty cool to repurpose things.
On the other, I question the "play from the end of the cabinet" design and the execution of the stick and buttons. And admin buttons on the back?
As to the sewing machine, from what I understand, those old Singer treadle machines are so common, they just aren't worth all that much, even when restored. However, the machine looked to be in decent shape. I could have seen maybe using some of it's elements in the cabinet somehow.
If you check out the before and after pics, it does look like he did at least some work on refinishing.