Not Christensen, Akro or Jabo IMO, it's getting whittled down rather quickly ( do you have a size ?). I know wonky Vitro's are almost impossible to come by but I'm still gonna vote a Vitro Blackie (also known as reverse Blackies) Newer type, the base is a thin dark color w/ the veneered blue, only marble I can think of w/ that specific color combo IMO. Though I've never seen one a fold crease or double ingot that's why I asked about the size ?? Oh, and the transparency ? I'm probably way off since I've never seen one as wonky as the OP, Vitro's quality control was unquestionably excellent. Just some food for thought
LINK :: https://www.allaboutmarbles.com/viewtopic.php?f=7&t=50788&p=366178&hilit=vitro+anti+blackie#p366178