Blenko #6721-S in Olive green By Joel Philip Myers 1967 and was modified in 1968. This piece was only offered with this stopper for one year 1967. The finial was removed for the 1968 catalog. This piece wasn’t made again after that. 

I have included the 1967 catalog pictures for when this item was listed . As well as the 1968 catalog pictures to show the modification to the stopper. The few examples I have seen of this item from 1967 all have blowers breath inside the ball portion of the stopper. Which looks sort of like snowflakes on glass and has one air bubble as well, the finial portion it perfect. The base is great with only slight air bubbles and no chips or cracks and no stains or cloudiness.