Well I just spent several hours checking through all my sources which have coins of Sept.
Severus from
Pautalia - I have dozens of them plus books. I also checked through the Kyustendil Museum (modern day
Pautalia) coin
collection but there is no coin of any emperor with a
centaur on the
reverse.
The thing that is odd about this coin is where the human
part of the body joins the horse's
part - there is a raised saddle-like thing there - normally it is seamless. Also
his front right
leg looks extremely long, reaching almost down to between the AV of the
legend, rather as though he is slipping forwards
out the saddle of a
horse with the
lyre in
his left knee which is slightly raised.
I did find a Hotel
Centaur in Kyustendil though and the fact that there are so many coins
from
Pautalia showing
Asklepios, it is very possible that the coin was struck showing
his mentor,
Chiron.