Markings on Bren mag box?

I wondered about the markings on the end of this Bren mag box seen on eBay?

What's the "EH304", the No1 and MK2 about?

Bren Magazine Storage Box | eBay

Magazine boxes were also designated by type and mark too. KG will correct me but it was all to do with the carrying handle. Some wre the BOX Mag Bren No1 Mk1 and 2 while others were the ±Box Mag Bren No2 Mk1 and so on whether you had a steel handle, leather or canvas. In real lide of course, such fripperies meant absolutely nothing at all. If the handles, whatever type were knackered, they were chopped off and went to the equipment bay and had new webbing handles sewn or rivetted in place.

I would imaging that EH could be a mis-stenciled VEH indicating VEHICLE 304 or 042 - or whatever budding picasso was wielding the stencil brush meant it to be