Office fag packet

Fell out of the wall when the electrician was rewiring.
One of my colleagues investigated it. The V&A have one like it in their collection, catalogued. It was found when they were unpacking some Egyptian antiquities. They weren't the cigs of choice of the pharaohs though, and they weren't left as grave goods for enjoyment in the afterlife. The packet was, like this one, empty. The date is estimated to be about 1920 (which fits in with the date of construction of our building).
It's all covered in "mill stour"- black sooty sticky stuff that was used for insulation.