Hey Lost,
When I first started experimenting making pipe pouches, I looked up tons of places and really couldn't find what I was looking for. It sounds like you have something very specific in mind that kind of opens up like a book? I've seen old books with holes cut out of the pages to store things and I always wondered how that might work as a pipe case. Of course, you gotta' figure out how to make the hole inside the pages (I guess drill four holes and jig saw it out?--but that seems messy).
I would maybe look up photos of older bags on ebay (maybe military bags--or better yet, go to an army/navy surplus store to get ideas). My pipe pouches are based on an old roll up chisel pouch I have and I thought the same design would work well for pipes. You might want to think about other bags that are similar to what you want but not necessarily made for pipes.
I'd be glad to help you if you're looking to do it on your own, or, of course, I can make it for you. I've made some RYO style roll up tobacco pouches. Maybe something like that, but for pipes?
In any case, if you'd like some assistance, let me know.