Here’s the 1920-S Lincoln Cent I mentioned in another thread. Just 46,220,000 were minted. She’s in AU condition and still exhibits a little red coloring.
Have you checked that 20S for an RPM? the MM position looks close to correct. http://varietyvista.com/02a LC RPMs Vol 1/1920SRPM001.htm
For their very high mintages the 19-S and 20-S Lincolns are actually quite tough to find in full UNC. Pretty much none were saved and the UNCs we have now are pretty much the result of random chance.