I've read of McClory's/Sony's plans for a rival Bond in the '90s.) Or were they allowed to make only one 007 flick?
MGM sued them and later Sony settled ceding any rights to making future (irony) James Bond films.
In 2001 McClory basically got shutout by the appelate court. So it's pretty much over. It doesn't really matter though. McClory only owned the film rights to Thunderball and like 9 or so alternative scripts, which were essentially all the same. McClory was sued in the 70's by EON for attempting to co-author an original James Bond script with Sean Connery. That got killed pretty fast.