HI,
My last word. I think all 3 pieces you have kindly shared with us, are all original antique or vintage garments. However, all 3 have been altered at some point to make them fit a new wearer, and a strong possibility is that this was done for use as a costume for a film or play...both to fit a new wearer/s and possibly to alter the style to fit a time period.
All the fabrics used in these dresses are clearly antique or vintage. The alterations are shown and obvious. I certainly respect the opinions of the others, and this forum has room for all to share, but my 35 years of researching antique clothing (including working with professional costumers for film and theatre) tells me they are not reproductions.
Although they may have been altered or used as a costume, to sell them as simply as "costume" may be a mistake, in my opinion. You would miss reaching the antique clothing collectors market who would still be very interested in these garments, regardless of the alterations.
OK...my two cents has been spent.
B