I set up braces clamped to the table to hold Elevator Skin open in the same way as was done with the rudder and right elevator. The open side of the forward spar faces forward which makes it a bit more difficult to hold the bucking bar while using rivet gun from the skin side. I found that a length of simple pipe insulation laid beneath the spar (Image 2) helps to protect the skin during riveting and makes it more comfortable on the hand holding the bucking bar. Image 3 shows all the Top Skin to Forward Spar rivets installed. No dents or issues.