What did the golden aegis look like? Antiochos IV actually had some of his bronze and small silver coins minted in Antioch depicting an aegis, perhaps the very aegis that Pausanias would see three centuries later.
The most famous Medusa from ancient times is the Medusa Rondanini. The marble Rondanini sculpture is an important piece of Cultural Property in Italy, and has been depicted occasionally on their currency such as the 1948 1000 lire note.
Janer Danforth Belson has suggested the Medusa Rondanini is a copy of the aegis Antiochos IV gave the Athenians. Belson believes “Classicizing features for the gorgoneion would have been chosen intentionally as an artistic tribute to the sculptural stype of Pheidias and his chryselephantine creation.” Belforth says “… the gorgoneion shown on this coin has many of the same iconographic features of the Medusa Rondanini rather than the usual round faces of the ‘grotesque’ type.”
If Antiochos IV's coins depict the Rondinini (or it's original) as Edward Newell first suggested in 1918, then Antiochos IV's aegis coin reverse provides an important contemporary reference confirming Belson's theory. Does the coin match? (Scroll back and compare them). I would say not much. It is possible the Rondinini only copies the center gorgoneion of the Athenian's aegis. Unfortunately the bronze coins are not detailed enough to make a positive identification. Antiochos also issued small silver coins depicting an aegis, but they are so small the gorgoneion is only a few millimeters across.
An even rarer coin type of Antiochos IV's depicts a side-facing winged head usually described as Medusa. I wondered if it could possibly depict the same sculpture.
First I had to find a side-view of the Medusa Rondinini. I had a hard time! Nothing on the regular internet shows the Rondinini from the side. I finally found the side view in Adolf Furtwängler's 1895 book Masterpieces of Greek Sculpture. I have placed it beside an image of the coin from the 2009 catalog by Münzen & Medaillen of the Roland Müller collection. The coin is rotated and scaled to match Furtwängler's picture.
I believe there is quite a resemblance!
Arthur Houghton and Catherine Lorber suggest the side-facing Medusa coins were struck at Antiochos IV's mint in Mallos. They connect Medusa iconography with later tetradrachms of Mallos that depict Athena with an aegis draped over her shoulders and back. This is possible, but I prefer connecting Medusa iconography with the forward facing aegis struck at the Antioch mint.
And with the Medusa Rondinini.