Sorry Lloyd, it is on the side of the box.

[Linked Image from i.imgur.com]

Apparently the Group name changed in 1963 to Imperial Metal Industries so 1940 now seems more likely UNLESS IMI were using up printed ICI boxes 3 years later (which is not impossible).

But the red factory seals applied after the boxes were filled say ICI so probably 1940 after all.

Last edited by Parabola; 08/15/23 02:51 PM.