I wore a dress almost identical to this in my cousin's wedding, which was in 1974! Only a different color. So, my recollection is similar to Gayle's. I think "Edwardian Revival" is a good term as well.
You might find, if you look around at the skirt seams, and in between the shell and the lining, a paper batch tag. I'm surprised there's no size tag, but not surprised at no maker's label.....