Since writing Well Met By Daylight, where I said that I had problems finding the manuscript collection for Folger VB26(1) (they date it at around 1577-1583 CE), it has subsequently come online. As such, I've had some time to both stare at it a lot, and pilfer the two images of Oberon/Oberion.
Here is the initial image, which appeared in that entry:
And here is Oberon looking very Djinn-like:
Here are the seals for his councelors:
And here is the 'very similar ritual' that Mr. Rankine mentions appear in Folger VB26(1):
You should be able to look at all of these images at their max size and view them easily enough. If not, you can always head to page four of the archive and pick them up.
Be seeing you,
PS. The images of Jupiter that appear in that collection? Just as hilariously awesome. I am so going to try and convince VVF to re-render them at some point.