Roman Coin ID (With Silvering?)

Hi Coin Community!

I recently purchased some uncleaned Roman coins from the Balkans, and this one turned out pretty nice. I believe there was a hint of silvering on it, which is more evident when the coin is wet. I'm guessing its a Gallienus Antoninianus, but I would appreciate any insight from those more experienced than me (which is probably the large majority of you!).

Largest diameter: 21mm

Weight: 2.81g

Obverse:
Right radiate head (with quite a hooked nose)
G or C followed by an A at 7-8 o'clock
N a little past 12 o'clock
S AVG from 2-4 o'clock

Reverse:
Standing woman with left arm out and something dangling down from the right hand? There is also a tendril-thing from the left hand going all the way down (not sure about any terminology here haha)
LV at 11 o'clock