Is It Edward III?

The scalloped border around the portrait and the two layers of motto on the reverse make this either a groat or halfgroat. Thanks for the weight and diameter; pretty severely clipped, but does everyone agree this is small enough for a halfgroat?

The challenge is the monarch's name (from about 12 o'clock to 4 o'clock on the obverse) has been clipped away. The bottom part of the legend can be read: GRA REX. So the legend is (king's name) DI GRA REX ANGL Z FR, most likely. Some Edward III halfgroats had this legend, but probably more read EDWARD D G REX ANGL... On the reverse, the clipped outer motto
was some slight variation of POSVI DEUM ADIVTOREM MEUM (I have made God my helper). The inner legend I believe reads CIVI TAS CAN TOR, for the Canterbury mint. Which raises another issue: I'm having trouble finding any examples of Edward III halfgroats minted in Canterbury. Still working on it.