Good guess imho.
The left hand one is the earlier model. It wants to be a "Buttermilk"--it just does not meet the criteria however. This is a very nice marble regardless of any name.
The right hand one---well these big ones do not always act like they should--it may be an early "All Red"---with no red😁.
I appreciate all opinions and wish for some more.
@Steph has a pretty good handle on this type of Vitro. I hope that she chimes in.
Marble--On!!