This tin of 5mm Pinfire cartridges was made by RWS in Nuremberg for Millard Bros, London.
Two layers of 25 rounds held by card. Only one cartridge as shown with a raised acorn headstamp.
It is 22.5mm case length and I hope was from the original contents.
How long was Millard Bros in business? I remember shooting Milbro air-rifle pellets in the 1960’s
and this was their trade brand.