2 Cent Washington Cut/Perforation Error?

Hello to everyone, I purchased a collection from a gentleman a few days ago. This stamp is a part of the collection and I've never seen a stamp in this condition before.Being an amatuer I consequently just don't know if it's that I've never had the opportunity to run across this variety of a stamp or if it's some type of an mint error that slipped through. Would someone please let me know the origin of this stamps condition and help me solve this puzzle for me? All opinions and theories are appreciated.
Thank You!

flipa,
It appears to be a imperforate stamp (corner stamp with wide margins), not an error, see here for some more info
http://www.stampsmarter.com/1847usa...d2imperf.htm
Don

Could it be a proof?

jmdregs....not a proof.
Just a imperf sheet stamp.

You have a copy of Scott 409 from the corner of the sheet. You can see the single-line watermark "P" from the back side. Worth about $1, perhaps a bit less since the removal of a previous hinge appears thin the top margin.

thank you all for your input I really do appreciate it.