Black Beaded 1920's Evening Dress

From the seller:

BEAUTIFUL ANTIQUE BLACK BEADED SILK DRESS, ERA 1917 TO 1920. BEADED BLACK BEADS OVER BLACK SILK CHIFFON.
Beads are black with a purplish, blue, greenish finish on them. I am not certain of the exact year, it is loose fitting with a dropped waist but the beading pattern is almost art nouveau.
SIZE MEDIUM, but this might work for a small to large depending on your measurements and how loose or tight you want it to fit.
There are no buttons at the side so this dress must be slipped over the head to put it on, but there are two small snaps at the left shoulder only to open that up.
There is no tag, I am certain that it was custom made and I am guessing here in the USA because I purchased it here over 40 years ago.
I would say that it is in good condition, there are no rips, tears, or stains, but the beading is loose in a few places.
MEASUREMENTS-
shoulder to hem 53", underarm to hem 45.5", armpit to armpit across chest one side 21", hips across one side 22", underarm to bottom of hip applique 13.1/4", armholes are 18" around, and the opening around the neck is 27"
These measurements are a little rough and I could be off a little at places, so please let me know if you need more measurements or absolutely exact sizing.

From Me:

1925 Fashion Plate

If you look at the black dress in the Fashion Plate above, you can tell it's very similar to the extant dress here - down to the gathered sides at the hip. Really, the only difference is one is beaded and one isn't. I don't know why the seller thinks this is post WWI and not mid 1920's.
I do like the arm strap closure on this one.