I sent a request on 17th December, via mail. I sent an LOR, and $1 (American).
I received it on the 2nd of February, but I could only post this today! I got two pictures, one portait of Steven as Glenn in 'The Walking Dead' and the other of him acting as a zombie alongside Andrew Lincoln.
So here are the pics...
The Glenn headshot:

The Zombie Shot:

And the envelope:

And finally, I used the address in the forum, via Steven's agency. You can see the address on the envelope too!