Large vintage lampshade in white opaline

Hello, here is a large white opaline lampshade, dating from the 70s. The lower edge is worn in places. This is the part that is inserted into a lamp. This does not pose a problem since it is not a suspension. For the rest, it is in perfect condition. The diameter of the upper collar is 10 cm. That of the lower edge to be placed is 29 cm. Thank you for your visit.