I was fairly certain this is from the 40s but I thought I would make sure since there are no zippers anywhere. There are no tags or labels either, aside from the dress shields that say “Kleinert’s Welllaundered.” I’m also assuming the fabric is crepe. It does have shoulder pads. It has small pinked seams. The belt is attached at the sides. I’m in love with the color!!
I audibly gasped when I saw these photos! What a swoonworthy suit! And yes, it has all the earmarks of a 40's garment. The shape/silhouette, fabric (yes, crepe), the peplum, pleating and overall tailoring and details. During WWII, along with fabric rationing, metal zippers weren't available, so button closures and ties on garments were widely used.
I agree with Marsha's dating and comments. WWII era. I would refer to it as a two-piece rather than a "suit." A fabulous find!