Why not send him a letter letting him know what you plan on doing- and asking if he would mind. I've done it in the past sometimes. I'm about to ask John Vanbiesbrouck if I can send him a stick.
Sometimes you have to ask to get an answer.
I've also seen some people send blank photo paper, and then print the image they want on it after the fact. They say it doesn't look like it was signed after at all- maybe a shot?
Maybe send index cards and print the browns logo on each one after too.