kc,
Strack 1135 knew three specimens with
head left,
Paris, Naples, and Modena, as Rupert has informed you on Numismatikforum.
On pl. XVII
Strack also illustrates the
Paris specimen. It is from the same
obv. die as yours, but a different
rev. die. It seems likely that there was only one left-facing
sestertius obv. die in this issue; the Naples and Modena specimens and any others that can be located will probably also turn out to be from the same
obv. die.
Cohen, disappointingly, did not generally recognize the desirability of the
rare portrait-left coins of
Marcus Aurelius,
Antoninus Pius, and the two Faustinas. So, according to him (
Cohen 710), your bust-left
sestertius was "Common", that is worth 1.5 francs or less, just like the much commoner bust-right version,
Cohen 711. Surely even in Cohen's day any advanced collector must have realized that these bust-left varieties were much rarer than
bust right, so worth paying a premium for!
The early
RIC volumes generally base their
rarity ratings uncritically on Cohen's franc prices, but here we should give the authors a little credit for independently rating your
sestertius "
Scarce", preserving Cohen's "Common" only the the portrait-right version. It would have been more accurate, however, to promote that "
Scarce" rating to say "R2"!
