Vintage 50s? Paul Sachs Original dress

Good condition Vintage 1950s? Paul Sachs Original dress with matching belt. Very light blue with off-white floral appliqués on the chest, right shoulder and belt. Side zip for closure about 14 inches. Works great. Belt has 4 hook and eye closures and looks like it may have been attached to the dress at some point but not sure Check measurements for modern size as there are no other tags for size or material. It is light and thin. I would recommend wearing a slip. There is no stretch. I think it’s probably some kind of cotton blend but not sure. Measurements taken flat from the back: About 46 inches long About 12 inches straight across the collar opening About 23 inches shoulder to shoulder About 20 inches pit to pit About 14 inches at the waist About 19 inches at the hip Note, there is no rips, stains or tears but there is some loose threads on the bottom hem and overall lightening/discoloration of the fabric. It’s hard to tell but in certain lights, it is more noticeable. I have not tried to wash or iron this because I don’t want to damage the dress as I am not an expert in restoration. This item is sold as is. Pictures are part of description. Please review photos and ask questions prior to purchase. Thanks!