Attached countersunk nutplates to top firewall, side brackets and panel. The nutplates are countersunk where the screw will go, but the rivet holes were not countersunk. I used a dimpling tool to dimple the rivet holes in .the nutplates. I then drilled and dimpled thefuselage pieces. I used solid rivets to secure the nutplates. I then used a larger dimpling tool to dimple the top coul sheet metal so that I would have a flush finish when the cowl is attached. Time consuming but worth it
