They are Vitro.
These are just different, not common to find.
The veneer is thicker, much thicker; the colors are not like a common Vitro color—close but less pronounced or vibrant.
The marbles have full coverage in most cases with no clear or whispy showing, although a few do have the recognizable Vitro clear with a wispy look.
These are from 4 different lots that I have hunted over the past 25 years. Two sizes so far, 3/4'” and 5/8”.
Steph thought that some of them may be some form of a "Bullseye" when I posted them back in July.
Marble--On!!