As for Philippe and Mathilde, they were engaged twenty years ago as you said in this post and they got married in December, 20 years ago, as well.
I really like Lady Tamara's 'winter' wedding gown. All other wedding gowns shown in your post were great.
In the Kent wedding pictures, Princess Elizabeth (as she was then) may be the only one who's still alive today. It depends on whether the other young bridesmaid (also sitting on the floor) is still alive or not. One of them showed two kings and a queen of Great Britain (future Edward VIII, George VI and Elizabeth II). In those pictures altogether, there would be 3 kings, one reigning queen, and one queen consort of Great Britain. I know Princess Juliana was present in one of those photos, who later became the queen of the Netherlands, but she was a foreign princess attending it.