Genuine vintage 1940s dress

This is a gorgeous genuine vintage dress from the mid to late 1940s (maybe early 50s). It's a rich black with cream colored dots. There is a side zipper and matching removable belt. At some point this dress was hemmed, and the extra material was tucked up into the inside of the dress, so if you're interested in lengthening it (or using the fabric for something else), that would be possible. It also has darts on the back of the dress with a bit of additional fabric tucked inside so a skilled tailor or sewer could probably let the dress out a bit through the bust and waist (they're hard to see, but I'm pointing to one of the darts in photo #8). One other really interesting thing about this dress is that it has 4 small clasps on the interior of the neckline (last picture). I'm not sure what they were for - maybe to attach a different collar to change up the look of the dress, or attach a slip, or shoulder pads, or to attach a pinafore or apron? This dress is in good shape but has small tears under each armpit (see photos). Dress is in otherwise good shape. I don't see any other damage. It has a very silky feel, but there is no label so I'm not sure of the fabric. It is lightweight.