Inboard bottom skin riveted on

I have completed riveting of the inboard bottom skin. I am now attaching the outboard bottom skin. The outboard is a little harder to rivet on due to it's size. I will have my wife Gretta help me out with this task. I can get at most of the top rivets, it's the ones on the bottom that are hard to reach. You have to reach through the second lightening hole in the ribs to get the bottom rivets on the rear spar. I have bruises on my arm from reaching in. For some reason the riveting really like to bruise muscle. I don't know if the impacting is causing it or not. However, I have been hit harder riding dirt bikes and not gotten bruised. Oh well. Blood, sweet and tears!