Bells like this come in a number of different styles and sizes. They are from Mexico and are often miss identified as antique mission bells.
What they actually are, and I have a couple myself just to show them for educational purposes, are bells made to look old for the tourists.
They are poorly cast out of lesser quality brass usually (which has too much copper in it) and assembled, then buried in the dirt to corrode for a while, sometimes under fire pits and other less appealing places to leach out the ash chemicals to hurry the process.
They are then dug up and sold. This has been happening for many decades but the practice has, as far as I know, pretty much died out. But that still leaves a lot of these old bells kicking around now! 😉
Basically you are looking at a vintage fake mission bell.
Interesting as such, but made to deceive and many a person has been taken in.