The Amon Carter has had several copies of many of their bronze works to show how the sculptures changed slightly in different castings both during the various artists lifetimes and posthumous castings. Some times the changes are as slight as maybe a difference in how a bridle is held or a boot is placed while others can be complete different finishes on the piece including a mottled or rough surface compared to a smooth one or a different choice in patina wich can give a whole new feal to the piece and what the artist was trying to convey in the work. It is rare that museums will put on display multiple castings of a piece for the public to view these differences directly.