BETO Taxco Mexico Sterling Pendant

This piece goes back to the middle of the last century. It is heavy and well made. I haven't cleaned it yet because I don't want to change the look of the pendant. I searched for a long time to find out more about "Beto" but so far he (or the brand) has been illusive. Someone referred to the the maker as "Maestro Beto" - I really know only that there are rather a lot of pieces with the same mark out there.

Thanks for looking:)