Came across this metal USB Box - looks sound and quite cheap too.
It also has free colour photo printing for on the top of the box 😃
link - https://www.tyndellphotographic.com/cd-dvd-usb-packaging/tyndell-metal-tin-usb-box
$5.25 US each box, plus delivery - no minimum order.
They also have some other interesting boxes and cases for USB and DVDs:-