Tacitus, AE Antoninianus. Siscia.

IMP CM CL TACITVS AVG, radiate, cuirassed bust right.
CONCORD MILIT, Emperor standing right, clasping hand of 
Concordia.
Mintmark Q
Estiot 2193, La Venera 1715, not in RIC (bust type), Scarce.

Sold on ebay in 2005 by AAH coins, wrongly attributed so sold
for only $2.12.