Misplaced Revenue Stamp

This document is for sale on ebay. I am not bidding on it, but the placement of the stamp seems a bit funny. Cancel does not match stamp placement at all. Is it possible that this particular stamp does belong with document and it was re-attached? The spacing looks about right if stamp was shifted up. What effect on value would this have if stamp has been re-attached, and would it need to be fixed?
http://www.ebay.com/itm/401379177269?rmvSB=true

The wording on the cancel makes it likely that the stamp fell off the document and was re-glued at some point.

If the stamp was re-attached with its original glue, it could be repaired by someone familiar with the process. If it was re-attached with white glue (pva), or a similar product, then that would make the item considerably more difficult to repair.

If you haven't done paper repairs before, then I would strongly advise against attempting a repair on your own.

Hi, is the document dated itself, if so can you read it and what is the date of the document/instrument?