Thanks for that reminder, Craig. I remain fascinated.
I have moved that thread to the archives, but I'll move it back out if someone bumps it for more conversation.
Dani's looks totally Pelt to me. From the texture of the base I'd guess it was mid-to-late 30's instead of the earlier years I associate with the more easily recognizable PPP's.
I have a marble which looks cobalt but has a lot of color inside which only shows up when backlit with a strong light. I've assumed it was Master. No idea why they wasted so much color inside such a dark marble.