Gamboa needs to be careful when he throws his overhand right, that he doesn't get caught by a lethal uppercut. I get the impression tho that Gamboa will be way too much for De leon to handle.
He fight in 2011 so he's shit by default. If he fought in the 80s he would've been great by proxy, if he fought in the 40s he would've knocked out just about any fighter today in one punch.