Well, after one hour of searching for my fellow Kindler I think I got something for you.
(I should be designing something but I'm not in the mood so I thought I could do something useful instead of surfing around with no goal in mind
) As I understand Periscope covers are made of synthetic leather
and you may see it here.
You may check this one too, it's "washable", it's from China and it's simply too cheap so I believe it is not leather
so I believe it is not leather.
Maybe I'm onto something, maybe not, at least now I'm familiar with covers market