Nice coin, I have about 100 at home from a hoard which a dealer sold me a year ago, same type of thing really Bronze ants from Gallic empire..Victorinus, Tetricus, Gallienus, Postumus, Salonina, Quintillus, but I am rubbish at attributing them, so have not bothered to date as I mean to sell them.
This is from a hoard too, its details are too strong to be a field find IMO. Finds from the Balkans can have good detail even when found individually, but generally fertilizers have done their damage on most field finds...unless they have been in a pot with others. Nice coin...Gallienus does look like an elf though in most of his portraits!