I've noticed that 'Orphaned' subsectors fall into three categories, those that are intended for non-Imperial settings, those intended for Third Imperium settings outside the official sectors and those intended for canon Third Imperium sectors.
This addendem specifically covers the second category. I suspect that most of the Non-Official Sector Imperial subsectors are going to originate during the period between Traveller coming out and the release of MegaTraveller. Anniversary and Orion subsectors as published in issues two and five of Alien Star typify this type.
My suspicion is that any such produced either appeared in fanzines or were the products of personal campaigns and thus created before the Third Imperium setting as depicted in the official setting books became the default.
As is also stated in the description of Anniversary Sector should I come across any more subsectors of this type if the subsector comes with the names of surrounding subsectors then it will go in it's own sector. Those that lack names for surrounding subsectors will be added into Anniversary and Nowhere Sectors in locations that will not conflict with the existing material.
Traveller Map has become not only a source for the canon Traveller universe, but also for some home brew sectors as well as maps such as the Distant Fringe created specifically to provide an alternate, but related setting. My own project of transcribing early material for the Traveller Map is specifically intended to preserve as much of it as possible and make it available to the wider community. However I am still not certain of just what is out there in the myriad of old Traveller Fanzines that have never made it to preservation. The one that I am most interested in learning the contents of is Ed Edwards 'Working Passage', this information has not been provided to the Traveller Wiki, but from the various references I have found it seems to have been a major influence on other fanzines of the period. The other is a fanzine called Between Worlds that is referenced in the advertising for Third Imperium.
Thanks go to those who uploaded AAB Proceedings and Tiffany Star to the Internet Archive and to those who have to date supplied me with scans of various subsectors.