Can the detector discriminate the horseshoe and iron buckle out, or are they seen and non ferrous targets?

Classic mixed metal target , Iron blade/Copper outer casing

Found this with my Manitcore, looks like an iron knife with 2 small copper rivets, found on a Roman site

Difficult target

Can the detector give a good diggable signal on 20 pence sitting on a difficult chuck of iron!

Odd one this, never thought a piece of Coke would mask out a non ferrous signal, but does it?

20 Pence above Horseshoe -20 Pence below horseshoe 6'' gap , how does this affect the signal

To demonstrate how distance between the ferrous and non ferrous targets affects the signals