Re: Do Skins/Decal's work on the leather back?
Decals aren't flexible enough to go into the crevices that exist in leather. A good decal (one with good glue) will stick to cleaned (meaning all the wax and outgass products removed) leather, but as SpookDroid said, it's going to look strange. And everywhere a tiny piece of decal is hanging over an inset grain in the leather, it's going to tear, unless, while it's wet, you use a very sharp Xacto knife to slice the decal the length of the grain and fold the edged of the slice down into the grain to stick to the sides of the crevice. (I used to do a lot of decal work on furniture when I was a kid - my father was in the business - and anything not glass-smooth never really looked right. [Imagine a screen protector with a few grains of grit on the screen when you apply it.] The imperfections in the decal will be tiny, but they'll stick out like a sore thumb.)