It doesn't. I'm just curious if it's the same "for Bren Gun" ammo that I have. If so, it's collectible, IMO. I'm sure you could sell it at a gunshow for enough money to buy an equal or greater amount of modern commercial.
Given that Brens were intended to use the same ammo as LEs and the sights are regulated for it, I'd have no concerns shooting it, as far as safety goes. It's probably corrosively primed, though.