If you’ve been following along, you know that RRC 308 was dated later in the RR coin series by Lockyear 2018, but it bears repeating if you’ve ended up on this page accidentally.
The unciae are in visual dialogue with the semuncia of this issue. The semuncia has a single cornucopia and the unciae have two.
Schaefer binder for further specimens, and also this second page
Based on Schaefer and trade I know of 19 specimens 18 with weights. Schaefer has identified at least nine reverse dies.
double cornucopiae aren’t unheard of later in the series. The most famous double horns are on the coinage of Arisinoe II, but the type was also in use on small bronzes of Alexandria in the last decade of the second century BCE (ANS illustrative set of search returns). Likewise, we find it (like because of Ptolemaic influence) on small bronze civic coinage of Laodikeia in Phyrgia , ditto Marathos in Phoenicia. Why Alexander II Zabinas (128-123 BCE claimed the Seleucid throne) would put this Ptolemaic design on his small bronze coins is beyond me but must have an explanation. I’m not getting stuck in the late Seleucid dynastic struggles today!!! (but will note motif shows up on coinage of Cleopatra Thea and Cleopatra VII cf. this one too)
The motif is also known on small bronzes of Panormus likely dating to 2nd cent BCE (cf. specimen in trade).
Ok. Dinner with family calls. Enough for today.
Liv Mariah Yarrow 
For another double cornucopia in the RR series see RRC 375/2. Not too far off in time from the subject uncia issue.
YES! which helped jog my memory of this old post to which I should link: https://livyarrow.org/2018/03/05/an-enigmatic-smile/
AND another: https://livyarrow.org/2016/08/18/sulla-at-vibo-valentia/