Actually the last winner of this that ran in the Queen’s Vase was Hartnell in 2014.
The winners that ran at Ascot since then have mostly run in the King Edward VII Stakes.
Personally, I wouldn’t rate the form of the latest Queen’s Vase that highly. A Group 2 race in which the first six home are covered by a fraction over two lengths is questionable form. They can’t all be stars.
four of the five declared ran in the Queens Vase , neigh on a question of do you trust that form to repeat itself, the one nagging me is the O’Brien selection, but will give the race a swerve.
Good luck Darren