I always thought that the Blackseal Sly was ordered by Panerai ( Pre V ) to Quorum, and that Quorum delivered them in March '97, just after Vendome bought Panerai.
The other interesting thing is that all the " regular " Black Seal were numbered P 001 to P 005.
So, we can conclude that the BS which are not numbered this way are fake, if I understood correctly the situation?
Best, and thanks!
Nicolas