I ran across this paper a little while back:
http://nytelecom.vo.llnwd.net/o15/ag...ports/1496.pdf
If you read all the through it's clear old stones were used to build walls. My interest was in American Leaf Tobacco Company (Topps predecessor) but they have the wrong one, the stones referenced therein were from a different company that existed a few years prior to Shorin's. Some big names are in there but alas no T206 or the like.