Look at the trim on the halter! Back in the day, we used to call these "rhinestones", but now we call them crystals. Even though it is many decades old, the trim is still impressive. There is even small crystal aglets on the ends of the straps.
You can see the label "Cole of California Original" on the bra
If you pull down the front halter section, there is another layer of the glittery fabric underneath, which is the cover for the bra (really unnecessary but obviously the kind of detail that was warranted in a suit of this caliber). Notice the darts that provide the shaping over the bra.
The suit is NOT Lycra or spandex but nylon (I am going to venture a guess and say it could be Lurex and nylon blend as it is very glittery and sparkly, but not smooth like spandex would be) Since there is no spandex, the back had to be fastened with a zipper! A metal zipper and a modesty panel behind the zip with a dome fastener for extra insurance against zipper slide downs.
The legs are finished off as what we would now call the boy short legs, but back in the day, that was the standard leg opening.
If anyone has an opinion about the date of this suit, I would love to hear from you! This suit has definitely brought some sparkle to my swimsuit day. Thank you so much Erin for bringing it in to show me!