...it might be 1960's -- I'm not sure. Either way it's very pretty and probably easy to duplicate. It's a very simple fitted top. The lace and attached chiffon scarf are what make it special.
Details: The bottom is formed by the scallops in the lace. (There's a wrinkle in one of them from this top being kept in a cedar chest -- also the scarf is a little limp looking from the storage.)
On the underside the chiffon underlining is simply straight stitched to the scallops.
How is the waist fitted? I could not get a good photo to show this until I happened to see the light coming through the top (it is a bit sheer). I then took it to the room where I have sheer curtains and pinned it up on them inside out.
Now you can see the waist dart! In the above photo the seam on the right coming down is the side seam - next to it on the left is the waist dart. It comes from the side and curves up. It doesn't disrupt the scallops and is nearly invisible on the outside. There is no shaping in the back.
The sleeve is a simple cap style:
Ah, the scarf! Made of chiffon (the same chiffon as the underlining), it's edges have a rolled hem. It's pleated into the seam of the left shoulder.
Then tacked down underneath on the center front. This shot is taken from the inside of the top:
And again tacked down just barely on the right shoulder (it's loosely pulled into pleats which are tacked -- I'm pulling it so you can see one of the stitches):
It then falls freely down the back where it flutters about.
The metal zipper is centered into a lace scallop as seen in the photo above. The zipper and a hook with thread loop at top:
Any simple button-up-the-back blouse pattern could be made like this. Instead of the buttons either put a zipper or perhaps buttons with button loops. In the photo of the inside neck further above you can see that the neck is simply bound with doubled chiffon bias.