Honestly, based on the size… it looks like it might be some kind of water tight cigarette case. Looks about the right size for a standard pack of filtered cigarettes to fit inside and it looks like there are solid hinges and a latch, and and maybe a gasket on the second image.
Editing Scoundrel: I had a moment of inspiration after cutting myself dealing with Christmas lights… did someone ever make one of these out of plastic?
It has a much better lid to body ratio than any of the cigarette cases I’ve been looking at, in plastic it wouldnt’ need that lip at the bottom, and looking more closely at the prop, there seems to be a seam around the middle, so there could be two glued bottom to bottom? My google fu is failing me, but I hope that helps inspire the search.