Well, the historic Panerai watches have a Power Reserve of 56 hours, based on the ETA movement...
The only Historic watch with a 8 Days Angelus movement is the Pam 203, a LE of 150 pieces launched in 2005.
The ETA Movement used by Panerai is curiously and very interrestingly designed as a Rolex Cortebert movement.
BUT, The " Manufactured " movements like the P 2002 8 Days Power Reserve are designed from the Angelus movement, clearly...
And they, as the Angelus, have a 8 days, sometimes 10 Days, power Reserve...
Hope you will find your way in this Italian Labyrinth...LOL
Best.
Nicolas