You just answered the question I have been looking for and I think I can answer yours. He is wearing a dress Macpherson modern and I think his name in John Macpherson. I have looked at several photos of the Macpherson gathering 2007 found on their official site and many on blogs about the Macpherson dress tartan. I am Macpherson but the fellow in the red plaid is an unknown and his tartan has caught my eye on a new purchase. Thanks