Finally uploaded into Wikipedia an improved version of a vector map of Middle-earth, here you can take it as well:
Download file (SVG, without geographic names, 2.2 Mb).
The initial map is not mine; as I can understand, its author is Chris Taylor who, for his part, had vectorized manually (!) the original map by Christopher Tolkien. Hope he won’t be angry 😉 My revision is minimal: I just removed a ‘bare area’ in Mirkwood (which is absent in the original map), added cays in the Sea of Rhûn and the lower reaches of the river Harnen. Will be glad if this map is useful for anybody 🙂