Yes, I'd go S1511 too. Ticks all the boxes - Annulet before EDWARD DEI GRA REX ANGL (no French title), Barred A in GLORIA, saltire stops. I think I can make out a lis in the central panel. The shape will be as on the shield, bottom right quarter bottom lis, rather than have looped side fleurs. A bit like a cactus. On the top image the initial cross is at 10 o'clock, then reads EXALTABITVR IN GLORIA.
The top image makes it look horribly cleaned. These aren't rare, so go for a better one if it looks too rubbed.