Finished drilling, deburring and edge-sanding the first W19-02 skin.
Used that as a pattern for the next skin, but putting them face to face, drawing the outline on the blank sheet, and drilling through the pilot holes of the first sheet to create the 2nd.
Every now and then I drill the hole into my work table a little deeper, then use a cleco to hold the 2 pieces together. The blue tape was what held them together until I could start placing clecos.
One W19-02 done
Completed skin to act as pattern, on top of rough cut aluminum sheet for second skin. Note clecos.
Clecos holding both sheets in alignment. You can just see the green lines tracing the "pattern".