Now, I can't find anywhere on the web the old version of GameSrv I used
(I remember was one of the earlier versions) and not only the last one won't work (as it failed the current one 2 years+ ago), but I'm back at square one trying to use net2bbs...

You should give Argus or Radius a try and have it load NetFoss before loading System/X, it should work just fine. I've tested it on several other DOS based BBS packages and they have all worked flawlessly.

--- Mystic BBS v1.10 A38 (Windows)
* Origin: Entombed :: telnet://entombed.darktech.org (46:1/134)
þ Synchronet þ thePharcyde_ >> telnet://bbs.pharcyde.org (Wisconsin)

On 09/19/14, Pharoah said the following...

You should give Argus or Radius a try and have it load NetFoss before loading System/X, it should work just fine. I've tested it on several other DOS based BBS packages and they have all worked flawlessly.

i forget which came first, argus or radius but you can also add taurus to
that list since the second and third ones stem from the first ;)

--- Mystic BBS v1.10 A52 (Windows)
* Origin: (46:1/132)
þ Synchronet þ thePharcyde_ >> telnet://bbs.pharcyde.org (Wisconsin)