Steve, yes it is a tough card and quite valuable. Also, just fyi the actual date of this card is 1920 (not 1921).
I have been collecting these cards for some time, feel free to contact me if you would like more information about them at
rhettyeakley@netzero.com
A few of mine can be seen here (at the top of the page):
http://www.starsofthediamond.com/e121.html
-Rhett