Antique SIGNED Large Cameo Sterling Silver Pin Brooch Achilles Armor Dragon

Description

LAST 3 photos are of a cameo sold at Bonhams in 2012, same subject as this one, which was not signed! That price was 9 years ago.
One of the rarest cameos.
SIGNED ON BACK, SEE PHOTOS.
Set in a silver bezel, unmarked, but tested sterling which was the norm in early Victorian times. Also a sign of its age is the actual pin which is longer than the frame of the cameo.
Tarnish / patina had not been touched by us.
We are not certain about who the figure could be , perhaps St George and the medieval dragon?
Any suggestions?
Measures approx. 2 1/4" by a tad over 1 3/4".
Last few pictures show you the same subject sold in Bonhams in 2012 for close to 0!
SEE ALL PHOTOS AND ASK QUESTIONS BEFORE BIDDING AS ALL SALES ARE FINAL.