But here's the tricky part. Vacor made some new ones ... called Rustic. Most of your marbles in this group look old but three of the marbles on the bottom right edge of the your last picture are what reminded me if this newer style.
I _think_ the Rustics are a heavier marble than vintage clay, but I formed that opinion long ago and I don't know if it is accurate. DETAILED INFORMATION (billes-en-tete.com)