The glass that the stands are on looks like float glass, which would make the stands, at least, post 2nd world war.
The engraved signature looks as if it was done with a flexible drive and diamond point, which also suggests more recent than your first suggestion.
Don't know the artist, though, so could be way off. Can't tell from the image whether they are cast, but assuming they are, this would probably confirm a more recent provenance. On the other hand, you may have discovered a contemporary of Amalric Walter or Decorchement!