If you consider your first pic the top of the mib, I think a pic of the front (the side facing the bottom of that pic) would go a long way toward a correct ID.
Here is a 1 1/8" (not including the little nub) sextuple ingot. It's Bill's marble now.
It takes some effort to see all six of the 5/8" marbles, but the volume calculation is spot on too.
I don't recognize this one either. Might be a newer JABO run. If it's vintage, my guess would be Heaton but . . .?
Did you notice the little fracture in the green striping?