I get rolls of unc cents for my grandsons to squish into the elongated cents. In a deal I picked up 20 rolls of 1970 s unc cents. I found two of the small date varieties. Very hard to find indeed. Below is a short article all about the 970 s cents.

http://www.ngccoin.com/news/viewarticle.aspx?NewsletterNewsArticleID=54