Yes their is a ring, a freind of mine just down the road breeds them, i incubated his 1st clutch and was left with her, she is number nine.They are fairly common around here, definatly far more common than people think, i know of 1/2 a dozen or so nests and have freinds that pull almost annualy.The next pic is of a wild Menalistic (almost entirely black) Haggard Musket. The guinifowl in the first pic weighed 1.5 Kg's This gives you an idea of what they are capable of.

Here is a pic of a freinds haggard imprint female( the sister of my bird)