Ah, the constantine, nice.
The zorro insert does seem to be coated brass although I cannot say 100%.
It is non magnetic and brass coloured under the coating, i scratched some off for a look.
Right click, view for larger image
The brass zorro war armor is a nicely made solid heavy lighter, too heavy for some but you’ll be used to that carrying the constantine replica. I carry the Ti version war armor.