I do not know any history of this or what type of metal it is made of. It looks like it could be a small replica of the plaque on the monument at Mark Twain’s grave. The image of Twain looks the same, and the design of tiered edges looks the same. The actual plaque does not have “Elmira, N. Y.” as part of it, and “Mark Twain” is written below it instead of on the lower corner. This item is about 4″ high and 3 1/2″ across and weighs 10.7 ounces, fairly heavy for its size.
Very good condition. Not sure if hanging device on the back is original. Photos do no show as the exact color of the actual object. On the actual object Twain is more grey-ish green. Also, photos make the object seem tilted or not square, but the opposite sides are actually parallel.
After writing the above, I found this link. It seems to support the likelihood that it is a replica of the grave marker and that the hanger has been added, as the one pictured at this link has a different type of hanger.
Book ID 5362