Lee, I thought I'd share a leather cover design that I absolutely
love. I have the
BLUREX Leather Slim Folio case for my Acer Iconia A500 pictured below. What I really like about it is the way it holds the device without obstructing the area near the screen in any way. You can't see them in the photo, but there are tabs at the bottom positioned in the same way as at the top. The tabs are curved and very stiff. They hold the device quite snug. There's a tab that holds the cover closed (probably not necessary), and the cover can be folded completely back.
I don't think you'd need to make it with the inner grooves for propping the device like the Blurex case, but you may be able to adapt your current design to secure the device in a similar fashion. You'd use less leather but may need material (plastic inserts?) to make the tabs very stiff, so I'm not sure how that would affect your production cost. Perhaps you could offer several designs and see which sells better?
I have a cover for my smaller 7" Acer Iconia A100 that's a similar design to the one you show, with leather around the screen like yours, and I don't use it because my finger's always bumping into the leather when I swipe near the edge of the screen.