The red one is modern. It's one of the mass produced ones. Some other looker may have dropped it for a joke, or someone may have used it to "salt" the area, who knows. From the style (no real type, no authentic flaking either) to the material, to the lack of patina, there is no doubt. Stuff winds up in weird places. The others all look authentic (one other looks like it could be modern too, but I might not have suspected it if the red one wasn't so blatant. One modern in the bunch puts the rest in question).