I guess I made the assumption that the OP wanted more than the Operator's Manual, that you can get from the Westerbeke site
along with a fair number of other documents.
63D Four Manuals Page
What they don't appear to have is the service/parts manuals for the "D". They do have those for the 63B/63C
, but I don't know the differences to say how applicable they are to the D. They certainly do share some parts, and the wiring
diagrams are the same, so don't know where any differences may be.
The bore, stroke, weight certainly changed significantly in that series, so for a rebuild
there have to be some significant parts changes.