Riveted stringer to skins, drilled out a couple of rivets. I found pretty difficult to achieve consistent result in the riveting due to the narrow space in the different location at the stringer position. the outer areas were easier to do, but riveting alone has not been an easy task and i had to drill out few rivets. i resolved to wait before closing completely the structure in order to have the opportunity to cross check with Lucio the quality of the work.