I keep mulling over this (when I really should be working )
My train of thought so far....
A 'genuine' person would have reported money the minute they realised it had been posted, therefore the sender is 'dodgy'
Dodgy person has your address.
Dodgy person can't get his money back cos you've involved the police.
In september when it's still not claimed you get to keep the money. Dodgy person still has your address.
2 choices = 1. send the money back to dodgy person to save your kneecaps or 2. email dodgy person and say "where's my PS2 ? - have you sent it yet" then file for item not received (whilst hoping dodgy person is daft enough to belive item is lost in post) Use the money to move house and spend the rest on chocolate.