In the below clip one will see Queen Victoria featured in the Winterhalter painting, what I hadn't noticed before is a massive stomacher which seems to have been part of the extremely large Cockade brooch/ element.The stones in the remainder of this jewel peice appears to be also very large diamonds.

My questions are as follows:

What is the provenance of the Cockade jewel?

Is the stomacher seen on Queen Victoria from her grandfather, King George 3rd or did it come into existence with her reign?

Is it possible that the cockade is part of a larger peice and if so where is its remainder today?

In order to get a close up of the stomacher you have to be able to expand the picture to see what I mean but it becomes fady on expanding.

https://commons.m.wikimedia.org/wiki/File:Victoria_in_her_Coronation.jpg

Regards,

Dave.