Are there two (or even three) sketches of Addisonian hyper-pigmentation?

Has anybody noticed that the Cassandra (CEA) sketch and the Stanier Clarke (JSC) sketch BOTH show evidence of Addisonian hyper-pigmentation? High-resolution images of these sketches are disappointingly difficult to find online, but do your best. Bring them up side-by-side on your screen and use heaps of magnification. Experiment with noise reduction, if your viewer has it; it helps a lot. I will mainly use the JSC sketch as a reference point, because most medical opinion agrees that it shows hyper-pigmentation consistent with Primary Adrenal Insufficiency (Addison's Disease).

Begin by looking at the right-upper eyelid in the JSC sketch. It is mostly black, but at the outer end it changes abruptly to pure white, extending in a crescent down the right cheek. In CEA the same transition is (arguably) just about visible. I accept that this is arguable, because in CEA the angle is not very friendly and the sample size is very small; but it is definitely possible to trace a consistency.

In JSC there is an area of darker pigmentation immediately above the left eyebrow. In the CEA sketch we see a shaded area in the same place; at a casual glance, one would take it for a shadow cast by the curly fringe, except that it doesn't resemble it much in outline, and we don't see a similar shadow anywhere else.

In JSC there is a prominent black spot immediately under the lower lip (probably blue-black in real life). In CEA, there is a hint of a dark patch in the same place. JSC also appears to show a less-severe but larger patch of pigmentation on the left upper lip, in the region of the left nostril; this pattern, too, is repeated by CEA.

Most telling of all, in JSC much of the left side of the face is severely hyper-pigmented, with irregular borders, below and forward of the left ear. In CEA the discoloration is less pronounced, and not advancing so far forward, but it has similarly well-defined borders which are too sharp, clear, and irregular to be mistaken for natural shadow. After noise suppression, this appears to be contiguous with the discoloration above the left eyebrow and, in a lighter form, extends down the left side of the neck - just as it does in the JSC sketch.

Overall, the pattern of hyper-pigmentation is more severe in the JSC sketch, which was almost certainly done by Stanier Clarke on 13 November 1815, when Jane visited Carlton House. This was around the time she began to feel positively unwell, and probably some years after the CEA sketch. Had Cassandra finished hers, it is possible those early signs of PAI would have been more clearly delineated; Jane evidently insisted that JSC represent them honestly. In both cases, however, the artist has made clever use of light, shadow, and composition to minimise the visual impact of the disfigurement. In the CEA sketch, particularly, the casual observer does not recognise the hyper-pigmentation for what it is, and mistakes it for the ordinary effects of light and shade. But the longer and more closely one examines it, the less plausible such a rationalisation seems.

Footnote: Astonishingly, the Godmersham sketch of a tall, skinny lady sitting writing at a desk, who may be Jane Austen, shows facial markings fully consistent with the above. Unfortunately the only image I can find online is hopelessly low-resolution and over-contrasty, so I'm not making an issue of it here. But post-processing definitely reveals a black right eyelid which appears to abut a white crescent running down the right cheek. There is indisputably a darker patch above the left eyebrow. An area of excessive contrast and shadowing makes it impossible to verify the black chin spot separately; but this dark area, as a whole, corresponds more or less exactly with an area of variegated hyper-pigmentation visible in the other two sketches, especially in noise-reduced CEA. These are too many coincidences to be ignored. Interestingly, there is a black spot on the upper right side of the nose, which does not appear in JSC. Perhaps it offended his sense of symmetry, or perhaps this sketch was done even later. Entre parenthèses, I wonder if any of this explains why Jane is facing AWAY from the artist in the bonnet sketch? Had she not yet come to terms with her condition?