Great uncle Harold's crucifix in leather flap

This is a crucifix affixed to a folded leather flap with four copper nails. There is an insignia on a banner above the crucifix's arms. I don't know what metal the crucifix is made of but it is very heavy and has never tarnished. I'm guessing it may be nickel. This belonged to my great uncle Harold when he was in the military (early to mid 1940's)