This was on the same page as the link : (yes- they are a hybrid)
Recipe For A Braggs Mountain Buff
Mi thoroughly a combination of about 40 percent Rhode Island Red or derivatives of Rhode Island Red (e.g. "Production Red", "Cherry Egger", "Red Star", "New Hampshire Red"), 20 percent Buff Rock, 10 percent Black Langshan, 10 percent Light Brahma, 10 percent Buff Orpington. For the remaining 10 percent season with traces of Barred Plymouth Rock, Jersey White Giant, White Leghorn, and Black Australorp to create a truly "All American Chicken". Spend the next eighteen years picking the most handsome and vigorous individuals for breeding purposes, while at the same time selecting for a golden buff feather color. Using an egg scale, choose only the very largest and highest quality eggs for the incubator. Then you will have your own replica of a Braggs Mountain Buff!
The alternative, of course, is to take advantage of the opportunity to purchase chicks from the original flock of Braggs Mountain Buffs.