Unusual metal box

[lssah2025]

I picked up this box since I have not seen one like this before, the seller didn't know what it is and I don't see any markings on it, possibly adapted/modified?

Possible MG ammo box?
Dimensions are approx. 7 1/2" Wide x 9" High x 19 1/2" Long

 

[reccetrooper]

Another example of this box is in this thread.

http://www.bocn.co.uk/vbforum/threads/97750-Unknown-20mm-Ammo-box-I-D-request