Spanish Lancers - Any Ideas?

I received these rather splendid fellows from John Holt at Warrior Miniatures and I am not sure how to paint them. They have rather curious looking headwear:

The only reference that looks anything like these figures is from a painting by Denis Dighton. The two fellows in the background:

Although the hats a slightly different, I will use these as the basis for painting, but would welcome any information that might help me with the uniforms.