Not in-depth research, but have you seen this article? http://heatherrosejones.com/stlouisshirt/index.html Written by a friend of mine in California after she got a chance to look at it in a museum.
Heather rose Jones's article is a great improvement on Dorathy Burnham's article, but these photos allow extra analysis.
For example, knowing that the armseye is sloped from Heather Rose Jone's article, the photos enable us to see that it's not a simple slope because the top of the armsceye angles back outwards again. (As noticed by michael poster of these photos)
Annother example is the bottom of the neckline.We already know that the binding forms a cross on the inside of the garment. And in fact in her photo we can see a third line - a vertical one following downwards from the point of the V. In the new phtos it can be seen more clearly. I was trying to bind a keyhole neckline the other day, using the cross method to end the binding, and it works, but not well. I was wondering if the trouble was it wasn't a V -shaped neckline, but this tiny detail gives me an alternative - the extra tuck taken out means that at the bottom of the binding there is actually fabric at the fold to cover, rather than trying to bind a raw edge. (I'm probably not explaining it well, but I can't wait to try that out on my next chemise)