I'm not sure on the specifics of this tartan, but I'd encourage you to check out "Scotland's Forged Tartans" by D.C. Stewart and J.C. Thompson. It's a study of how the bogus tartans dreamed up by the Sobieskis came into existence. The other book that you might like is "The Setts of the Scottish Tartans" by D.C. Stewart. Some errors crept into tartans as threadcounts were published. One good example if the Culloden tartan. Not only are the colors in the currently woven version different than the original colors, but the threadcount (particularly the width of certain stripes) is off. I'm not sure how each mill determines the threadcount it will use, but hopefully someone will chime in.

Cordially,

David