Funnily enough I was going to go the other way and say that the text is too sharp. As you are trying to capture the text as being written onto the map and not printed on afterwards I think there needs to be different levels of fading and not just one level of opacity applied to the text layer. Any old text that has been around a while doesn't fade all at the same place, but there seems to be patches where the text looks faded more in some places than it does in other (I did a lot of referencing on my last CG Mapping Challenge for old books). The method I used was when I had all the text done then throw it into its own group (Photoshop) and apply a mask over the top and just brush over the text in areas with a large low opacity (10-20%) brush so that its faded in places but can still be read. Now I'll admit it still needs to be legible throughout so you need to pick and choose the places you do it, as Korash said it is dependent on the background.

Another thing I would perhaps try is trying flattening the text into one layer (duplicate the group) and using the Transform > Warp tool to pull the text around slightly so it isn't a consistently straight text. In some maps straight uniformed text is fine, but I think if you are trying to make it look realistic (with the stains, etc.) then go all in

The biggest part where this map falls down though is the compass rose, the use of the emboss tool doesn't look like an impression has been made into the paper as it's way too deep with those shadows. For my money I'd maybe try and recreate a blob of wax seal and put an impression into that if you want to go down that route with that effect.