I've always loved your crystal sphere charts. I've seen people do these various ways but the parchment thing really sells this as a fantasy map (and lessens the impression that Spelljammer is a sci-fi thing).
This version of the Greatspace map has some great things going on.
I love your Hellenic-style Greatspace logo and think the logo should be the logo adopted for the cover of any netbook that ever gets developed for the crystal sphere.
The helmet, horse riders and woman-like column give a Hellenic feel to the parchment. Seeing those riders reminded me that the world Thesalys needs to have some epic battles in its history and those riders could easily be from one of the many city-states that existed before the Time of Unity.
I wonder if you could put something like a sketch of Castle Skyview (the palace on Thesalys that Greatspace is ruled from) onto the blank areas of the map.
There is one element that confuses me (although the full size map might make this clearer). You have some writing on the left and some squiggly lines. They look a bit like they might be cross sections through mountain ranges, but I can't quite work out what they are.