The mortuary piece could hardly have been missed, and then listed later as an afterthought on the possession list as some suggest.
As Christer states, it was not missed.
Halse noted it was missing before he heard about the GSG rag
Halse: I came through Goulston-street about twenty minutes past two, and then returned to Mitre-square, subsequently going to the mortuary. I saw the deceased, and noticed that a portion of her apron was missing. I accompanied Major Smith back to Mitre-square, when we heard that a piece of apron had been found in Goulston-street.