I think I need to take a closer look...send him to me.
What a freaking cutie!!! I am actually inclined to believe he is a boxer/staffie mix. From what I can tell from the pics, I see both - the ears, crown, and somewhat of a square jaw look very boxerish, as does his deep chest. But the eyes, longer snout and stockier build are quite staffy-ish. It's a good look for him - he's a doll!