Is this vintage or modern-made from a vintage pattern?

And is there anyway to know?

I initially thought that it was maybe 50/60s based on the construction and style but there is a nylon zipper in the back. However, when I compare the zipper color to the dress, the dress is black and the zipper is a dark blue so it could have been replaced at some point? Or do you think it is just a more contemporary dress made from an old pattern? Anyway to be sure? The lighting is terrible so the first picture was darkened to show the true color of the dress

Thanks!

 

I also think it is true vintage. Is it possible that the cloth part of the zipper has turned color over the years, and was originally black? Can you show a close up photo of the fabric of the dress?

 

The zip is probably cotton and the dress fabric looks like it could be nylon/of man made fibres in part or whole. Repeated washings will fade the dyes in black coloured garments, but cotton will fade faster.