The Met has some incredible Delman in their collection. Judging by the soles, I would think these are a remake from their classics collection - the company was briefly brought back from 2013 - 2023, so it would not surprise me if they put a more modern touch on the classic shape and style that was originally very Avant-Garde and risque. Soles were not made like that in the 40s, they did not have those modern markings. The style of platform heel is very 40s. The flat/squared front was not really a 40s thing, but for a master of creating wearable art for footwear, it might be replicated exactly as it had been designed. It also is odd that the inner label is not centered, so maybe these were a sample or for use for a fashion show.
Editing to add, all of the modern ones I'm seeing have the same off-center logo. I'm guessing whomever brought the company back to life was not selling exclusively high end, like the original.