I've known about the modelling of puppets on real people. The 'James Garner incident' concerning Troy Tempest in Stingray comes to mind. Sean Connery was imitated a few times with Scott Tracy, Captain Paul Travers of the Zero-X, and Captain Grey. The most incredible example is probably the character of Father Unwin in The Secret Service, an exact replica of the face of Stanley Unwin, who voice him (And doubled for him in some of the live action inserts!)I find it a little hard to believe Sylvia had no idea she was the inspiration for Lady Penelope. Given she voiced the character, came up with the concept for the character (And nearly all the other Anderson characters!), designed some of her outfits, consulted the sculptures... there's just too much she personally did for her not to know