Thank you! Is the reason you say Vitro because the veins appear to end at polar seams? I cannot see a seam, but the linear correlation of the ends along a line suggest there might be one. Is that your clue for Vitro? I have this sketch in mind:
Here is a detail photo of the area (within the ellipse) I am wondering if it can be defined as a seam:
For Vacor, I was focusing on the bubbles within the clear base.