I don't doubt the prop replica looks nice. I've seen photos of several and they all look "identical" and not in a bad way. The types of creases are very similar. In short, it's a very precise work for the calligrapher who did them.

That said, it's a treasure map, not an area map like ours. It's also done by a calligrapher, while ours is done by Sapiento. So there's that.

Again, thanks for all the advice. I plan to follow through with the bits that will be safe for the paper, and only use coffee/tea as an experiment. There's a Ranger distress ink called Tea, so probably you can do a decent job of just simulating teabagging (there, I said it).