Right lad...This should solve it...go to the item what you`ve bought,click on "order details" there you should see his address,look at the post code on the screen..also ask him aswell what his post code is..
Then..look on the reciept that you got from the post office,look on the reciept for "Destination address" underneath that it will say "building name or number",below that will be his post code,then below that it will say "address validated" - Y
if the postcode on your screen maches the postcode on your post office reciept,it must have got to the correct address,then,because it had a tracking number,go to royal mail "track and trace" website,put the tracking number in,it should say successfully delivered to then his post code..
i reckon the next thing you should do is ask for his email address,take a good readable photo of the post office reciept,then email it to him,let him see it for himself lad....also tell him to go to track and trace and type the tracking number in,so he can see it..
I dont want to risk losing this stereo i have wanted this one for like 20 years, hell if it comes to it i will get my buddy to pay him again via paypall i will just put a claim on the po because there is suposed to be electronic viewing of the signature of wich there is not at the moment, something very fishy going on 