This cover is a unique combination of a philatelic disaster and an error cover.  It was sent from St. Lucia to Grenada. 

It was sent from the Government House in St. Lucia to A. W. Lewis, K.C., in Grenada.  It was underpaid, so a 2d due stamp (SG D13a) was added.  What makes this both important and special is that this is the error of the broken back to 2.  As far as we are aware, this is the unique known error of this type on cover!  It's valued at L50x20, but it doesn't stop there. 

When a fire in 1927 made the post office device  in St. Lucia unavailable, a temporary handstamp was used.  This rare handstamp was only in use for 6 days!  Truly, a case of Murphy's law in action.  Everything that could possibly go wrong did, but in the end it makes for a cover with a great story and greater rarity!

This lot is over $100 USD so I will ship it using priority mail in the United States, and registered mail overseas.  This is to ensure that it reaches you in a safe and timely manner, and includes tracking!