Nellie, I concur with the thoughts on Queen Elizabeth's crown and the Lahore and Turkey diamonds. That's how she was crowned in 1937.

Crystals were made and currently are set into the crown. However, a lot of mixing and matching used to go on, and not only transferring the Koh-i-Noor from Queen Mary's crown. Because of size similarities, Cullinan III and IV could substitute the Lahore and Turkey. I have read that, when Queen Elizabeth wore the crown (minus the arches) at the 1953 Coronation, it was set with both the Koh-i-Noor and the Cullinan IV.