I like the Front on LB2 alot.
The LB1 front is "almost there", I would zoom in to the cover image more with less of the tan gradient. Both backs could be integrated more with the spine. As they are, the transitions are a bit harsh.
Cheers,
Ben
Edit: for example, getting rid of the black line between the back and spin on LB2 then letting the "red stamp" carry over into the back (but behind the character artwork), might do the trick