In some earlier discussion (maybe even this one) you and I discussed Osiris beds. In my own research the earliest example of one I could find is from a Dynasty 12 pyramid complex at Lisht, and the status of that example (as some form of Osiris bed) has been questioned.
I've done some research on this and have read plenty about Osiris beds and related funerary paraphernalia, and cannot remember reading of an example—even on conjectural grounds—from the Old Kingdom. This is not to say such a thing is not known, but I personally have never come across mention of it. Can you provide a source or some other avenue of citation?