I suspect it is
IMP M ANNIVS FLORIANVS
AVG, coming from the last issue at
Ticinum. There are no examples from this issue with this
reverse listed in
La Venera but there are examples with the above
legend for the other
officina for this issue:-
The following lists the examples with this extended
legend in LaVenera
PRINCIPI IVVENTVT, //PTI,
RIC -, 1 example in LV, Draped and
cuirassed bustPERPETVITATE
AVG, //QTI,
RIC -, 1 example in LV, Draped and
cuirassed bustINDVLGENTIA AVG, //VTI,
RIC 66, 3 examples in LV, Draped and
cuirassed bustCONCORDIA EXERCI, //VITI,
RIC 59, 2 examples in LV, Draped and
cuirassed bust, 2 examples in LV,
Cuirassed bustSo an //STI example is not unexpected with this long
legend but would appear to be quite a
rarity.
These reverses were re-used to make up the first issue from
Ticinum for
Probus as in my example below.
I think you have made a very nice find.
Regards,
Martin