Well, there is everything from soup to nuts in this lot, which spans many, many, years of marble production. All I can say is that I hope you find some good ones!
You're on track, left and lower are Buttermilk variants and the upper is a Superior. The best Buttermilks have less white showing but these are really great marbles, regardless.
Huh, I didn't even notice the blue until I enlarged the photo - i was thinking it was base showing through white or something - you know how it can look sometimes.
It still looks foreign to me, I don't recognize it as anything American.
I do think that green is most common in that matte finish but I am pretty sure I have others too. I'll dip into the archives and try to post a pic later.
So it is still a No. 00 size, which is greater than 1/2" but less than or equal to 9/16". They are still pretty uncommon and l keep most that I find. I like the 9/16" size Vitros for some reason.
I have quite a few of those, I think some of them just came off the rollers that way since I have some in a Tom Sawyer bag. Not sure why they would have that matte finish though.