Following the instructions, I clecoed together a nose and inboard rib and then used it to trace out the shape for the cradle. I had some old particle board shelving, and used that to make the 4 pieces, tracing out the shape onto each one. Then I cut it all out on the bandsaw, cut some aluminum angle for a base, and screwed the angle to the bottom of the cradles, which will allow it to be clamped to the workbench.
Over the weekend my goal is to get all the HS parts primed and ready to start riveting. Depending on timing, I may also get started deburring and dimpling the skins.