Front of Cover With Standard FDOI Cancel
 

Reverse Cancel Eight Days Later
 

This nice generic cachet was created by Griffith Cachets and features the Liberty Bell.  One interesting thing about this cover is the cancel found on the back.  The reverse cancel is dated April 9, 1965, eight days after the official FDOI cancel found on the front.  I have not been able to discover anything about the cachetmaker.  Please let me know If you have any information.  I can be reached at smith@in.net.