I have a full grid and two of the characters - perhaps the easiest to locate with Mr Google. But he is of no help with the other two, though I know where they must be lurking. Any ideas about where to find them in a reference book/site?
Is there an error in the clue to 7? I agree with others about what it must be, but the def is to a slightly different word (unless there is an obscure meaning of sap which C doesn't seem to acknowledge).