There are two known, extant boas:
1. The King's Road Boa owned by Ruth (and possibly used by Rocky in the film)
2. Columbia's Boa owned by Larry
They have a lot in common and appear to be made from the same materials, however the order of their layers is different. They both begin with a length of black twill tape (grosgrain will work well, too). Both boas also begin with pleated chiffon on the ends - it's a little droopier and gives the boa a more tapered appearance. Both boas have multiple layers of pleated (most likely) Organza, but the lengths and positions of the Red and Yellow are reversed. The tassels appear to be the same.