As far as I can tell, these just popped up last night or this morning. The prices aren't great, but at least Best Offer is an option. For anyone who has been searching far and wide for these elusive titles as you seek to complete your 7800 collection...
Ikari Warriors: https://rover.ebay.c...tm/253739510979
Rampage: https://rover.ebay.c...tm/253739098110
Fatal Run: https://rover.ebay.c...tm/253739066969
Impossible Mission: https://rover.ebay.c...tm/253739582610
Double Dragon: https://rover.ebay.c...tm/253739127946
Midnight Mutants: https://rover.ebay.c...tm/253739543624
They also happen to all be from the same seller, so I'm sure you could get some shipping savings by purchasing multiple games from him. I have no connection to this seller whatsoever, just passing along these recent finds. Cheers.