My Mum had Pyrex so it's familiar but until I looked into this little nesting bowl I had no idea there is a whole world of Pyrex. Man, I was down a Pyrex shaped rabbit hole for days.
This, I can therefore tell you with authority, was designed in 1957 and produced until the mid 1960s. It is the Amish butterprint model: 441 or 1 - 1/2 pint sized bowl. The design is still sharp and crisp and glossy, it has been no where near dishwashers which are not good for Pyrex patterns. Inside it is a little scuffed on one side, it has been used as you would expect, but no chips or cracks. Reflected in the price.
Dimensions 105mm high by 195mm wide