It certainly has the same hasp as the bren chests I've seen and the 100 round drum magazine chests of which I have two (with the magazines i might add
).
Interestingly enough, the clasp/latches are common with the exterior stowage accessory hasps on a humber. I have a set of those off a landrover that I need to use to make up some shell can mounts for the rear wings and for one of the front wing mounts.