So I finally finished whipping the top gown fabric to the heavy linen interlining. I planned to attach the hooks & eyes to the interlining and put the lining on top, in order to avoid them pulling and showing the lining.
So I pull out the gown tops to start measuring, and I find this:
So I ripped out the stitches, flipped the fabric around, and whipped it down again. Then I was finally ready for hooks and eyes: