IIIII,
Great find! RiverBBS.net was down for a long time, glad to see it's back up. I contacted Mitch (SYSOP of River BBS) a while back, great guy, really pissed off about this patent when i chatted with him, especially when he too saw digital audio/video before 1990. He has offered to provide testimony to the files he has on his machine, so he is definitely helping out.
I had never seen a FLI file that had actual images (usually just animation/cartoony stuff)... awesome find! And thanks for converting it to a viewable format for us, because some of these old DOS programs just don't run under a DOS shell.
I will add this Sachiko file to my prior art page, crediting you for the find.
Excellente!