One thing that's always puzzled me about that kit is the name. The ship was commissioned in 1637 with the name Sovereign of the Seas. She had a long, active career, and two name changes: she was renamed Sovereign in 1651 and Royal Sovereign in 1685 (on the eave of the Glorious Revolution). She underwent a major rebuild in the 1660s, emerging from it with the official label "ship of the line." Not a whole lot seems to be known about her in the way of details, but there are several contemporary paintings of her at various points in her career. It's pretty clear that during that 1660s refit the bow structure was extensively redesigned and rebuilt; she came out of the refit looking quite different than she had originally. And that was twenty years or so before she was renamed Royal Sovereign.
I'm no expert on seventeenth-century English warships, but it certainly looks to me like the Airfix kit represents the ship as she was built. So it seems to me that the model ought to be labeled Sovereign of the Seas.
Arthur Ward's The Boy's Book of Airfix (I really don't like that title) says it was one of Airfix's first two sailing ships (the other being the Endeavour). Both, according to Mr. Ward, were originally released in 1963. Considering its age, it's a mighty nice kit.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.