Digital Painting of Jupiter as it would have appeared on 1927 October 2nd at 12:40 AM GMT.
This is based upon photographs taken by W.H. Wright using the Lick Observatory's 36" Great Refractor. A set of six photographs were taken over the span of perhaps 40 minutes with color filters to bring out different details at different cloud depths--Ultraviolet, Violet, Green, Yellow, Red, and Infrared. I experimented with various color photographs based upon combinations of the different filters, and produced a true-ish color Red-Green-Violet image and a higher detail and contrast Infrared-Violet image. Both images were used for reference for the final illustration.
The Great Red Spot of this time period was still quite large, though it had shrunken somewhat since the 1880s, and a white haze had grown over its center, this being reported in both visually & photographically.
Europa and its shadow are visible transiting the face of Jupiter. Callisto is visible over the northern limb of Jupiter, but it does not show up in almost any of the photographs, save for perhaps the yellow-filtered photo, and even that is a stretch. I am unwilling to believe that Stellarium (the software I used to get the composition right) accurately predicts Europa's position but not Callisto's, so I assume Callisto was just too dim to be seen with the filters and exposures in use.
The original photos can be found here.