Boussac 1988 connects this imagery on a Delos seal impression (bullae) with Athenian New style tetradrachm symbols of Xenokles and Harmoxenos
The most likely date for this issue seems to be 91-90 BCE
We never get this 3/4 profile seated Roma on the Republican coin series, but we do have her seated with her right arm crossing her body and her left on a spear/scepter.
Earliest seated Roma on Roman coins:
CF. Pistis coinage of Locri (Pistis on this blog) which is MUCH earlier
A lovely specimen sold in 1910
Liv Mariah Yarrow 