I will try-
I have a copy od MTW's 'Gravitation' on my shelf downstairs, but I have to go up for another laser run in a few hours...
How is this for a theory: "Dark matter is actually lost copies of MTW's book 'Gravitation'" given how massive that book is, it would take only a few copies to make up the missing mass...
P.S.: You might want to ask D.L. what he did when we had the 'W' of M.T.W. over for dinner when D.L. was in Kindergarten...