Not a huge mess. In fact I won't hesitate to do it again.
Well the sound is definitely coming from the drivers side. Also, it seems like it's coming from up top. A rod hitting the rocker is what it seemed to be. That might support getting new rods.
maybe run it some more. you can replace the right v. cover, since it is OK on that side
Try running it again and try touching the rockers to see which one (s) is (are) making the noise.