The corset is finished. I'd still like to further refine the top, which is not giving me quite the shape I want. Maybe time for bust gussets instead of general shaping.
I made a pleating board using some internet tutorials. The basic process:
Two pieces of poster board, hobby/paper craft knife, ruler, spray glue.
Mark lines for your pleats on the larger poster board. I found a sequence of 1 inch, 1 inch, 2 inches worked well.
Use the knife to score, but not cut through the poster board.
Pleat the poster board, spray the back with glue and firmly affix it to the smaller piece.
You now have a board where the pleats open on one side. The idea is to stuff your fabric into the folds, the iron them so they stay.