For sale are two sets of four glasses.
(8 available total, sold in two separate sets)
 
We have been unable to fully substantiate whether these are from the line of pieces designed by Josef Hoffmann, and made by Bieffeplast. This is partly because the line encompassed a fair few designs. However, we similarly - upon rigarous research - have not been able to determine that they are not, either.
And based on the specific design, and era they appear to be from, we feel that they quite likely are.
 
Note that the metal holder comes off for easy cleaning of the glasses.