A very nice find. I have a small collection (just over a dozen examples) of these long form SEVER, IMP VIII coins but do not have an example of Fortuna standing. I do have a couple with her seated but from different obverse dies.
Obv:- L SEPT SEVER P-ERT AVG IMP VI-II., Laureate head right
Rev:- FORT REDVC, Fortuna seated left holding rudder and cornucopia

Obv:- L SEPT SEVER PERT AVG IMP VIII, Laureate head right
Rev- FORTA EDVC or FORT REDVC (R corrected from A), Fortuna seated left holding rudder and cornucopia

I do have a coin from the same obverse die as yours though....
Obv:- L SEPT SEVER P-ERT AVG IMP VII-I, Laureate head right
Rev:- VICTOR AVG, Victoria standing right, left foot on globe?, holding shield with left hand, resting on knee, inscribing with right hand
Minted in Laodicea-ad-Mare.
Reference:- RIC 486 var. BMCRE pg. 113 var. Cohen 704 var.

Which I have die linked through the reverse to a different obverse die
