Hi Y'all

Well, I know its a little OT, but period cowboy equipment does touch upon several areas of our hobby.....
And for my tenuous weapon link, doesn't James Stewart kill the badguy with one in 'The Naked Spur'?
So anyway, here is a sadly single Mexican made (I think) antique Spur with white metal inlay.
I'm hoping someone will have some info on the designs used as they don't seem 'usual' to me (not that I've seen much of this sort of stuff).
The 'stars and bars' are what are puzzling me. Is it possible that this was made for a US customer?
It's stamped on the inside with 'I.S.V.M'
Mexican cowboys must have looked fantastically stylish!