25HP Heater Boxes X Cover Plate

The partnumber of this piece is unknown to me.

I have a lot of part manuals but none of them show this X plate like in this early exploded view. (Note: See the two piece cilinderhead engine tin)

Top x cover plate is used by VW on the 2-piece crankcase.
Bottom x cover plate is used by Porsche on the 3-piece crankcase from 1954.