Ok hate to be the one to mention this but....
If you sleeve your frame in that spot it looks like you will be reenforcing the Crumple Zone. Not exactly a good Idea, that could cause your air bag to prematurely deploy in an accident. Or deploy when it normaly would not have. The sensor for the air bag requires so much "shock" to set it off. If the frame doesent crumple in a lower speed accident you could inturn set of the air bag.

I dont claim to be an expert on this but it is just an Idea. Personaly I wouldn't screw with the acordian looking part of the "frame horn".