Compare my first foto (center/middle of the deck surface) with the foto of the block pictured in post #7. The #7 foto of the deck surface in the middle appears to have two small holes that go clear through to the water jacket, not one hole and the shadow of a rusty hole like mine.
On the other hand, in the #7 foto I see the small water jacket holes in the rear center of the deck surface, but no indication of corresponding holes in the front center of the deck surface.