EF
The bottle opener ones have a little dip or ‘tab’ on the hanger
Bottle opener
http://www.tias.com/13227/PictPage/1923093137.html
Horse Brass
http://creekbed.org/collection/images/horse-brass.jpg
Also, Brasses were stamped or cast. Both can be repro, newer but authentic, faked or real
I’m no authority, but try to pick brasses in shapes I like with decent detail (but not too much, some look like detail has been added back in). The stamping or casting should be good quality (stamping is less common than casting). You want decent edges; wear from use, not overcleaning or rubbing to make old; cleanly punched holes part of design. Older brasses often have “gets” or little posts where cast brass could be held for polishing, but fakers sometimes add those too. Supposedly the Indian copies have a coarser surface on front or back.
For me the best policy is look for quality look and then enjoy.