I tried to find a leather binder and could not find one that would really fit. Then I remembered that I had a binder for pencils and pens, which I had bought in Europe twenty years ago. They are very popular there, you use them to neatly organise colored pencils, pens, erasers sherpeners etc.
There were a lot of loops for the pensils, which I eliminated except of one, then I glued some velcro fastener on one side and the appropriate mating pairs to the back of the Sony. Then I glued a piece of acrylic sheet on the other side so that I can attach a PostIt sticky pad to it. This way I always have my reader handy and something to put notes on right with it.
Unfortunately I do not have an address to buy the leather binder from, however I would think that a little googling should bring something to light.
I enclosed a picture which shows my custom cover.