I do not know that they were photographed on the same day. If the theory is to be salvaged at all, it would require the John Ray photographs to have been made in 1960, while the other was made in 1958. (We have LorenC's word that he found one of the Gilbert Photographs in 1958. We do not know for sure that this is true. ) Again, if the theory is to be salvaged, it requires two different women in two different years, but both wearing the same shoes and jewelry. (Yeah, it's a stretch.) The only thing making this remotely plausible is the difference in Chin sizes between the presumed 1958 pictures, and the presumed 1960 pictures.
If Frank Davis was making money doing naked photo shoots I don't see why he would stop doing it from year to year, or stop using the same props. Perhaps he just likes those shoes and jewelry, and perhaps the one girl reminded him of the other.
This is, of course, stretching plausibility, and is very unlikely to be true, but it does seem to me that the chins are different from one girl to the other, and the resemblance is questionable.
When you see a hoof-print, you normally think "Horse." But a hoof-print can also be left by a Zebra. I doubt this is a case of a Zebra, but it doesn't hurt to wonder about it until we know for certain that it is a Horse.
Speaking of Horses, Why the long Face?