The currently posted Autochromes lack density, contrast and color saturation when compared to the original Autochromes that I have. They also lack the distinctive grain pattern evident even viewing an original Autochrome by eye.
The first 3 can be attributed to the silver quantity coated, the lack of the black pigment grains, and perhaps spectral sensitivity or dye quantities used. The second item may be attributed to the resolution of the scan, the fineness of the silver halide grain or the size of the starch particles.
As you see, there are too many things to ponder here to sort them out just by this simple viewing over the internet. The appended photos are the original box of stereo Autochromes that are in my posession and a scan of a 6x6 singlet from a pair that pretty much duplicates what the eye sees in terms of color and grain.