Is yours a different die from Ferrando's?
Yes,
He differentiates between
bust types and
obverse breaks, which makes it rather complicated.
The laureate
head right is the main
bust type, the
cuirassed, a rather
rare one, with p*AR and S*AR. It is with hthe second
officina coin (F 455) that a dot is visible between the XXs.
The same
mintmark also occurs with the laureate only
bust for both
officinae.
There are, however some special ones: dot S*AR and CONSTAN dot - TINVS
AVG obverse. So the conclusion can be that
Arelate 'did' something with dots....
Frans