If I recall correctly, I bought this decal set for a Cub project and Iseem to remember that it had the Contintental marking. I could be wrong though.
http://www3.towerhobbies.com/cgi-bin...?&I=LXCRD9&P=Z
If you also do a Google image search for "piper cub continental engine" you get soem pictures that show the logo stamped into the rocker cover. Not the best images but they might give you something to go off of.