Awesome! Thank you for the corrections! I actually found a reproduction of that biography that I'm going to purchase.

Far as Tartan, I know they are a very recent thing, but I did find this:
http://web.ncf.ca/fr307/mary_graham.htm

"James, the 5th Earl and 1st Marquess of Montrose (known to history as the "Great Montrose") was a kinsman of John Graham of Claverhouse and they fought side by side on behalf of their monarch, both dying for their cause. An account of their kinship is given in the family tree."

She suggests "The Tartan of the Grahams of Montrose" would be most appropriate based on that.

Thanks again! So at this point I have no idea why we would have this wooden carving of the Scrymgeour-Wedderburn Earls of Dundee arms in my family along with some Claverhouse stuff. But I'm very glad to have sorted what was evidently a very large misconception in the family.

Alex