I’m struck by how Brutus’ name is written with serifs and Lentulus’ is not. I want to keep an eye on serifs. and think more about it as a stylistic feature. RRC 500/7
HCR 60701 (RRC 500/5) seems to suggest that is is just engravers choice?
Serifs
adventures in my head
Liv Mariah Yarrow 
Suggesting, or hinting, that there were different celators for the obverse and reverse on this issue. At least that is one possible explanation. Worth keeping an eye on serifs to see if some other significance can be teased out.
I like this idea! Will keep it in mind!