PAX PVBLICA

Laureate, draped and cuirassed bust of Pupienus right, seen from three quarters back. 

Pax seated left on throne, holding branch with the right hand and a scepter with the left hand.

Photo of a coin sold the 17/05/2017 by Classical Numismatic Group, Electronic Auction 397, lot 642, link to the sale: https://www.acsearch.info/search.html?id=3835908, link to their website: https://www.cngcoins.com/.

For the legend break on the reverse, we could note PAX - PVB - LICA _ SC. I chose to consider that there is no legend break because the scepter does not cut the legend, it is inserted at the beginning of the space between the two letters. Same thing with a coin preserved at the British museum, Museum number R.16586, shows a larger space between the letters P and V of PVBLICA. I also did not list this coin as having a new break because it seems to me that it is the letters V and B which are closer to the others. These letters P and V are therefore as far apart from each other as the other letters, with the exception of the letter B which is closer. Link to the coin: https://www.britishmuseum.org/collection/object/C_R-16586.

I observe that on most of Pupienus' coins the cuirass is almost invisible and the shoulder appears smooth. Although I have listed a variant with a non-cuirassed bust for other emperors from the same period, this bust of Pupienus seems to be cuirassed. We see streaks indicating a cuirass in the lower shoulder or at least an irregular lower shoulder showing a desire to display a cuirass. Here is an example:

 On this photo the streaks are visible at the bottom of the shoulder. 

However, we cannot exclude that only draped busts exist. So far, I haven't noticed an example where the shoulder is undoubtedly smooth.