Images upscaled by R-ESRGAN 4+ Anime6B & ESRGAN 4+ in the first roll to 1600x1200 and then upscaled by R-ESRGAN 4+ Anime6B & ScuNET PSNR in the second roll to 3200x2400.
Some images have also been denoised before the first roll due to corrupted faces caused by compression artifacts and GFPGAN/CodeFormer.
I've held the original images for many years and I don't really know where I got them. You can check this gallery as an original reference: /g/874772/9348b1b464/
Interesting experiment. But I think the skin tones look quite faded compared to the originals, especially on the breasts themselves. Makes them almost look like implants at times. There is also a bunch of shading details that didn't make the jump when upscaled.
Aside from other small imperfections (mostly around the eyes and chins) it looks ok, but quite good for an A.I upscale set. I definitely would still choose the originals though.