Speaking of maps (on an entirely unrelated tangent), I just found this:
http://web.archive.org/web/19970306195638/www.bungie.com/inside/images/map.jpeg
as a part of Bungie's old website, the page in question of which can be found here:
http://web.archive.org/web/19970210021744/www.bungie.com/inside/inside.html
I noticed that they're the same art style and had some interesting ideas involving the angles of the top of this lost map and the bottom of the known Myth map, but I'm not sure they pan out. Thought you all might like to see for yourselves, though. (Remember to compensate for the difference in North on both maps. The lost map is rotated 16 degrees clockwise compared to the Myth map, according to the compass points on both of them).