Is my grandmothers eveninggown from the 40'ts?

Thank you so very much for your help!

 

Thank you! No there's nothing at all on the other side.

 

It's definitely European made, possibly French, not American and probably not British - the overcast selvedge, the use of hessian... These are typical of French and some German makers, also probably Swedish, but dressmaker made, not manufactured. Is there a mark on the zipper pull (opti, eclaire?) The tear drop pull is also more typical of European zips, but it looks suspiciously like it may have been a replacement. An early zipper should have brass teeth or brass that has been painted black, or shiny black celluloid. I would have to see it mounted on a form, but I think this could be just postwar - c. 1946ish, or possibly wartime although evening gowns are rare during war in Europe after about 1940 (Although Sweden was neutral and had more social occasions, so it could be wartime Swedish). It could be 1939ish, but the draping strikes me as more wartime/postwar.

 

Thank you so very much Jonathan!
I always thought it was made for her, since I have another one of hers with almost identical cut.
Yes, I do think that the zipper has been replaced, especially since it's about 10 centimeters too long for the seem.
Wartime would make it swedish, since there's no possible way that she would have gone to France and have dresses made for her, and my grandparents were no friends of Germany, at all.
Do you have any idea at all about the material in the sholder pads? I'm just curious, since I've never seen anything like it.