If you go to this link:
http://www.hanoverbrass.com/ , then OUR BUCKLES, then on to page 5, you'll see some orginal and reproduction snake buckles. Look for these numbers:
G-36 Snake Buckle
(Blockade Buckle)
circa 1861-1865
TG-36(A) Snake Belt Plate
Original dug Cold Harbor, Va.
TG-36C Snake Belt Plate
TG-36B Snake Belt Plate
original dug (Seven Days Battle, Cold Harbor, Va.)