Thanks! The Sarna article says it tied for "Best Accessory" at the 1996 Origins awards (the external link is defunct), so 1995 makes sense. ...and if I'd actually
opened the book, the art on pages 5 and 7 is also signed '95.
I see three possibilities: these files could have had their dates messed with (doubtful, as nothing else seems out of order); these could be playtest files from whoever ended up putting the FS9-O and BJ-O into 3058; or the Virtual World simulator pods had already added Inner Sphere Omnis by 1992 (this seems most likely to me).