Vintage faceted glass stopper, Bolle, Bullicante, embedded 1 bubble, geometric

This is a vintage, possibly 1960s, faceted glass bottle topper with controlled bubble. I have seen a lot of stoppers over the years and this one is unique. The process of including a controlled bubble is called bolle or bullicante. This particular stopper only has 1 bubble, right in the center. The coolest thing about it is because the stopper is faceted, when you turn it, the single bubble multiplies into four bubbles, creating a geometric pattern. So, it's also a conversation piece! Condition - excellent with some roughness to the bottom of the stopper. It is POSSIBLE, this stopper was created in the 1960s by Jozef Hospodka, a Czech glassmaker. The stopper was in an auction lot of other glass pieces including 3 other pieces of Czech glass, one of which appears to be a Jozef Hospodka piece or made from the factory he worked at. It is known that Hospodka created bullicante pieces. 3.75", approximately 5" circumference at top 3" circumference at base bluebin checked