Arts & Crafts type question

Any hardcore "crafts" type people out there?

Assuming a "money no object" type situation (ok, it is but I've spent over a year working on this so far, and there's still another 12months+ of work to go, so don't want to ruin it by going cheap now), and you wanted to recreate an old style treasure map type book, what sort of material would you use to write it on?

I'm guessing the old books you see in the likes of "Indiana Jones and the zimmerframe of death" or "National Treasure VII" would have been written on some kind of animal skin thing as opposed to paper (yes I know they're just movies, work with me here) but has anyone come across anything suitable in modern materials?

The covers I'd imagine I could do with some kind of leather bounding and a fabric stitching, but the actual pages I'm at a loss for.

ETA
Thanks to the power of LJ Communities, I've had these suggestions
Egyption papyrus
calf skin parchment
sheep skin paper (also has the thread available for stitching the pages together for the binding)