Invited to speculate - that's got to be 50% of this thread...
However, look at what happened to the Asiana 777 which hit a sea wall then pirouetted on its nose down the runway then belly flopped back onto the ground. What bits fell off that? The tail cone due to the impact on the sea wall, some undercarriage parts and the engines. The fuselage stayed intact.
So what would happen with a relatively slow and level impact with the water, perhaps following an invented RNAV STAR to an imaginary airport 50 feet above the ocean? I would say the same - the tail may have remained in place without a hard strike but engines may have been lost. But the fuselage could have stayed intact. Engines would have sunk immediately, followed by the fuselage after a few hours. Given 2 - 3 weeks delay what would be still floating? Even if the wings and tail had broken away they may well have sunk. But after floating for 2 weeks or so would be nowhere near the fuselage which itself would not be near the engines which would have sunk close on vertically.
Beach-combing for debris may not be very productive.