They are based on the c. 1740 stays in Norah Waugh's Corsets and crinolines with only the side back seams taken in a little at the waist to fit my shape better.
I constructed them my usual way. After outlining the pieces, I quilted the boning channels.
I inserted the boning, secured the edges and whip stitched the seam allowances down. Then I made the lacing holes.
Then I whipped the seams together, made horizontal boning cases from linen tape in the stomacher and then bound the stays.
Lastly I added the lining.