1840's Dress Remade into an "Colonial" costume

From the seller:

This antique Victorian era blue cotton batiste pink moiré floral print polonaise dress gown 1776 costume dates from 1900. It is made of a cotton batiste fabric, with a pastel blue background and pink moiré watered wavy floral print. There is an off white ecru color embroidered net lace trim collar and cuffs. This charming colonial costume 2 piece dress has a polonaise bodice gown, with a white pleated cotton front insert panel, lace trim flounce ruffle shawl collar, long sleeves with lace cuffs, hook closures down the back, a cutaway, draped, swagged side pannier overskirt and is lined with stays, boning sewn inside. The gown measures 46 inches long, with a 24 inch waist and 32 inch bust. There is a matching fabric long floor length full skirt worn underneath the polonaise gown missing the back closure and is unlined. The underskirt measures 35 inches long, with a 24 inch waist. It is in good condition, but has not been cleaned, with only a faint small stain on the front top of the skirt and some slight fade discoloration on the shoulders (see close-up). This is truly a wonderful piece of Victoriana 18th century costume wearable art!

From Me:

I don't think this is from 1900. Rather, if you look at the waist seam, you'll see all the handsewn gathers that look like they want to come together to a point in the front but the white placket not-a-stomacher thingy is there instead. If you got rid of the lace and added-later white placket, you'd have a perfectly reasonable summery 1840's dress.

It was common in the early 1940's for theaters to take older garments and pretty much destroy them to make costumes due to rationing. I have one such victim (1710's fabric with 1710's embroidery made into a 1740's style frock coat with nylon lining). My guess is this is another victim of rationing. The white placket thingy is to hideous to be associated with the centennial dress (ie, they would never do that in the 1870' - it would have looked much nicer) and, in the 1900's, they would have added something ridiculous like pearls down the front.  1940's makes a bit more sense.