An update of sorts, anyway. I contacted the St. George's Society of New York through the link provided by lazygardens. The very prompt response I received stated, "It's a nice chair. The arms depicted are the British royal arms. The execution is not perfect but there is no mistaking the design." Unfortunately, this pretty much reiterates what I wrote and doesn't really tell me anything additional. I wrote back requesting more information, but haven't heard anything since.