Thanks Bob, very interesting article.
BTW, after my uncomfortable immersion in Spanish heraldry, I posted some info on the CMH site which I soon realized was inaccurate. The cannon marking using varous crowns did not follow the "official" dates of introduction for new COA's, because when I checked surviving 17th C. examples, I found a transition point that lies somewhere between 1628 and 1673, as opposed to the 1700 date indicated by the heraldry information.