leather for bellows

I know most of the bellows maufacturers no longer use leather for making bellows. I understand there are probably much better materials out there and this is probably the main reason why they don't. Not to mention the costs. But if someone wanted to make a leather bellows what would be the requirements for the leather material. Soft, pliable, and yet strong I'll assume are the basics. But what about type of leather? Goatskin? Sheepskin? What about thickness? .4mm or .5mm maybe? Then what about surface? grain? Any and all thoughts appreciated. Thanks

These are the measurements from my Century 8x10 view camera's original bellows:

The original bellows has three layers:

Inner layer: 0.008-0.010 inch, fine black woven fabric with a black coating on the side toward the ribs.

Middle (ribs): 0.012-0.014 inch, very firm and brittle cardstock.

Outer layer: 0.008 fine woven fabric with a textured vinyl pattern in burgendy color.

Total thickness with glue, etc. = 0.028 to 0.035 inches.

I believe the Ebony bellows are goatskin?

From what I have found, you normally find goatskin skiver in nice supply of .5mm to .8mm thick, not so much for other types of leather except the composite leathers (ground and reformed to sheets). You can get these types at a book binders supply like http://www.talasonline.com/