It seems like your count is pretty acurate, although I do not know the exact number they have found.

I think you are right in saying that the boilers are still in place in the bow section. I never could understand where people got the idea that Titanic "barfed out her boilers" when she was on end, as they were pretty fastend in there with the uptakes and everything attached to them, plus the bulkheads.

I guess the only ones we see outside of the wreck have spilled out from the breaking point. There is none in the stern as its section starts at the reciprocating engine room.