Can anyone help identify this paper weight that was my grandmother's? It measures approx. 3" x 3" and contains a flower with single air bubble. The dome does have a beautiful blue cast which I've been told is a bit unusual and that it is probably american. It is lightly signed on the bottom "Spi.... or Spl.... or Spu.... like Spilbaut or Splibuaf very hard to see but beneath this is "1922" which is clearer and beneath that very faintly is #34
Any help will be greatly appreciated.
http://glassgallery.yobunny.org.uk/displayimage.php?pos=-7687