My father had a report produced by Halberts Family Heritage. I'm not sure wether it's a bunch of BS or not, but this is what it says about the Rockwood Coat of Arms.
"The Rockwood Coat of Arms hereby illustrated is officially documented in Burke's General Armory*. The original description of the arms (shield) is as follows: "AR. THREE CHESSROOKS SA. A CHIEF OF THE LAST." When translated**, the blazon also describes the original colours of the Rockwood Arms as: "Silver; Three black chessrooks; a black upper third." Above the shield and helmet is the crest which is described as : "A silver lion sitting and facing the observer, holding a black spear with a gold blade." * I expect that for a fee, you could draw whatever you liked and have it registered with Burke's Armory. ** The implication here is that there was something written in Norman French which required translation. Bear in mind that I could write something in Latin and tell you what the translation was, although that would have no bearing on the antiquity of the words. Maybe that sounds too cynical, but I think that cynicism is in order. Regards all, Jim Rockwood