Rome Mint Curved Roofline Campgate

Constantine I, AE3, Rome, Officina 2 CONSTA_NTINVS AVG High-crested helmet, cuirassed bust right VIRTV_S AVGG Campgate with six rows, three turrets, closed six-paneled doors, no star above, top and bottom rows empty blocks, curved roofline P | R in fields RS in exergue RIC VII, -- Note: Bust type D7 not attested for three turret series in RIC. Only the second curved roofline example I've seen in the 5 years I've been collecting campgates.