In 1981, Judges Guild published Dave Sering's Maranantha-Alkahest Sector, at the time an approved Traveller product, though it was declared invalid by GDW in 1984. Also, in the Aug/Sept 1982 issue of Pegasus, Judges Guild published Edward Kuns' Tagret Sector (whether they realized they were revising an area of space that they themselves already already covered remains a mystery).

Later, the Gateway Sector was published by Digest Group Publications in The Megatraveller Journal, #4. It was apparently for Willian H. Keith's Lords of Thunder Campaign (circa 1120-1123). The sector was designed by Thomas A. Dundee. Once again, the same area of space was reused... new star positions and everything.

Hope this helps.