I just discovered that "An Atlas of Fantasy" by Jeremiah Benjamin Post has a map of the Witch World in it! There were two editions of the Atlas and I'm not sure if it's in the 1973 or 1979 edition, as the 1979 edition dropped 12 maps and added 14 new ones, or if it's in both. I'm trying to find a source which list which ones were dropped and added and if there is a scan of the map online somewhere.
In a 1979 interview with Andre on http://andre-norton-books.com/index.php/witch-world-saga, she mentions it and comments that "quite a few more towns and important sites have been added"… so it may be the map was reprinted from the 1973 edition, if it's in both editions, and wasn't updated.
I'm curious to see how it compares to the versions printed her books.