I have already made the changes to our instance of dspace. Here is an explanation of what the tombstone functionality works at our instance.
When an item is withdrawn the user is presented with these options for
the reason of withdraw ( these reasons live in the file tools/confirm-withdraw-item.jsp ):
Removed from view by legal order.
Removed from view by the University of Michigan.
Removed from view at request of the author.
The user makes his selection and the item is withdrawn. When the item is accessed the reason for the withdraw is
displayed in the box containing the bitstreams.