Hi Milero,
Though the seller says it's 60s/70s, I'm more inclined to say it's from the 70s or early 80s. Horbowy created his "Antico' range (bubbly soda glass) in the mid 1960s at Huta Sudety, but started experimenting with color and opalescence in the 70s and 80s at the then newly formed Huta Barbara.
It's a really nice piece.
Anik