The photo shows recently recovered remains from an 1890s cargo ship that was used as a blockship during the First World War:

There's an anchor coming in from centre-left below which is an object with a rectangular face-plate.
A crew member on the barge carrying the remains said it was an "engine rocker". I've done some googling, but I don't know anything about ship engines and probably didn't use the right keywords, anyway I'm still none the wiser.
The crew member said the section above the anchor shank is the curved arch of the wreck's stern, with the vertical section on the right being the bottom of the keel above which (ie to the left) the rudder was once fixed.
The chap also said that other members of the crew thought the squat L-shaped item at top left may be the top of the rudder post (ie the rudder once lay between it and the bottom of the keel to the right).
Can anyone identify, or confirm, what the objects in the photo are, please? (especially the engine part, of course!).
Thanks

John Latter / Jorolat