I sent a letter and SAE to Antonio as well as 4 others in one big envelope on: 14th September 2012, and today I recieved 3 signed photos back from him.
address I used was:
Manchester United FC,
Sir Matt Busby Way,
Old Trafford,
Manchester
M16 0RA
Here is the pic, only putting one on, as they are all the same., only with bigger writing.