Wow--great first post! I agree with the others here that you have captured well the feel of a map of this genre! Well done!

As for feedback I had to think hard, but here are a few (purely cosmetic, "icing on the cake"-level) ideas:
1) Although stereotypical, I would ragged-up the edges. Would increase the feel even more.
2) The wax seal has a red glow around it--a black shadow would make it "pop" even more + be more realistic.
3) When you look very closely, the crease in the paper (which I absolutely love, by the way) does not bleed through to also crease the drawing itself. This is pretty easy to fix in PS.

Again, awesome map. Welcome to the Guild!!!