Odd looking box/Container?

[banny]

Hello Chaps,
I found this item in a British position and I can't place it (it could be Japanese)
someone mentioned it looked a bit like an ammo box, but the size and the slits in the side which are the same on either end, don't look right. All the sides look too clean to have been rusted away, so it may have had a lid and bottom.
It looks like some sort of attachment that goes on the side of something?
Any ideas would be greatly appreciated. Cheers.
.

[Gary J]

Looks like a battery box of some type ..

[Danmark]

Strike Banny - not much to go on!
Alls I can think of is a cover for some electrical box ( fuses / relays ) and the slots are for ventilation.
Cheers, Dan