It took me a while to find out what pattern could be used. This came out of it (except for the lid and the belt loop).
Looking for leather stitches I have chosen this one. It starts with a single row of slant stitches.
In the second step you add a symetrical row. It can be worked with two needles as well.
I have an impression that the crosses should be near each other, but as a compensation I have nice same crosses on the wrong side :)
The middle is made of a thicker piece of leather to hold the shape. I made the holes in advance for them to be more regular (as you could already have seen on the pattern picture).
I like the work with prepared holes. I'm just afraid there'll be too much fibre, the crossed seam might not have to be straight.. We'll see.