I have the same box, with the same American seller’s label on it. I have never been able to find out anything about either company.
The ammunition that was with my box was British Military surplus Ball Mark 2Z, with headstamp: B^E 45 9MM MK 2Z
The ammunition is common, and since the box label doesn’t represent a manufacturer, but rather only a repacking of surplus ammunition, I can’t imagine this ammo having any high value. If the boxes are in nice shape, perhaps worth a little more than shooting ammo, with the box label being more of a collectible than the ammunition in my view.
My box has never been the subject of much excitement by visiting collectors over the years (I have had it for probably 25 years, at least, even with those that collected boxes and didn’t have it.