I, too, question the potential of Imperial provenance/presentation (if that is the thought). IMO, the appearance/finish particularly of the interior do not appear "professional" enough, if it is suspected to be in the original state. As the FA has said, there should definitely be hall-marks, and yes, usually the central design would prominently show the cypher of the monarch (just to let everyone know from whom it came!). IMO, it DOES strike me as well, as being a (potentially LATE) commemorative piece.
Is the box known to be a replacement? Hopefully, if original, it would show an attribution imprinted into the top lining. Likewise (if a presentation piece), a depiction of the Imperial crown or Imperial cypher would usually adorn the top of the box.
Without actually seeing the item, these are simply my impressions. Good luck on your findings! Regards, AP.