I might have some left, but it won't be much and it won't be in those dimensions. I got a couple of pieces from a tree that broke behind my church during Katrina back in '05. I cut it into about 2-3 inch slabs with a chainsaw and made some boxes out of it. Its very rough, but should be plane-able. Whatever I've got has been air-drying in my shop ever since. How much do you need? I might even have some osage of about the same dimensions and story.
Shoot me a PM. We'll talk.