Vitrified little NZG pot from 1948 - 1955

I haven't seen this shape before, which is very exciting, however, I cannot find a shape number for it.  It is too big to be an egg cup and if it is a mustard pot it's a big one ??
It may have had a lid originally ....?

Many thanks to Melody for bringing this to Te Toi Uku yesterday to show me.
Just waiting for some measurements

Edits to add measurements:  59mm high x 51mm wide

I will pop this into the Crown Lynn with No Shape Numbers Gallery

I have seen these before with the same NZG backstamp
they usually have a lid