The 1876 Z1-S Seated half dollar counterfeit is part of the Ostrich Neck family which includes 1876 Z2-T and 1876 Z3-T Seated halves. All varieties are known struck on brass planchets. This variety appears to be slightly more common than the 2 other varieties in this family.
 
This example has a decent level of wear and a weaker strike on the obverse than usually found. The obverse is easy to identify with the oversize 7 in the date. The long-neck of the eagle is also quite diagnostic. This is an inexpensive example of this hand-made die variety, and I'm surprised that I haven't offered or sold this variety before.