Thanks for trying but my picture is a bit out of focus on that side, just looked @ ring with my Loupe 10x and it says "STER" figured it was short for sterling silver, but maybe I am wrong ?
Yes, it is southwestern style, and it is a cast piece rather than a handmade one. The little C in the circle is a copyright symbol so I'd guess they made a bunch from the same mold. Here in the states it isn't required for metalsmiths to register their maker's marks so it can be very hard to ID many maker's marks.