Hello and welcome to the glass message board.
You may well be right. Glass blown in a metal cage is something you find in Spain a lot - and what you find it in Spain you will also find in Mexico. It was the 1970s and 1980s when suddenly all of Spain filled with metal caged table lights, hanging hall lights, garden ornaments etc.
I do not know if this production took place in Spain itself or in Mexico - or in both locations.