I thought I’d solved this! Williamsburg’s jacket and petticoat combination, accession number 1990-10. Here’s why: “East Indian textile, worn in Albany, New York, by Ann Van Rensselaer, ca. 1790, textile earlier in date.”
1790 I can wear at work and at Dress U. That makes it fun and useful, which is always better.
Then I woke up at 2:00AM, with this KCI dress in mind:
That’s a dress style that could be worn with the white Ikea curtain petticoat and kerchief. Now, I’m better at jackets and petticoats than I am at gowns (though isn’t an open robe really just a jacket with a crazy-long skirt?) but I can’t get the KCI gown out of my head. It’s English, too, which makes it plausible, if not as close as the Rensselaer gown. Bonus: have to pattern it up myself, which I enjoy. Just because I’m swearing doesn’t mean I’m not having fun.
I have until March to get something finished. First comes some more standing around in the cold, and sewing for men who want to do farm work.
Kirsten Hammerstrom 
Absolutely beautiful, and fascinating, to review and ponder! But I have a question — as someone fairly new to 18th C construction–why did they pin the dress fronts closed? I should think it would be so hard on the fabric, to be pinned at each wearing! Didn’t they have button-loop (or buttonhole) or lacing treatments? Or were those considered too intrusive to the line? Not to mention the danger of getting oneself skewered in a clinch, …or scaring off the clincher…
Best
Nancy N
Pins maintained the smooth, cone-shaped line that was considered fashionable in high-style gowns. Lacing over a stomacher is seen, but stomachers are pinned to stays or gowns.
Later, some edge-closing gowns do have hooks and eyes, but buttons are really rare.
Pins are mentioned as a deterrent, or at least annoyance, by gentlemen.
Janet Arnold’s book shows closure methods pretty well for the mid-to-late 18th century.