Mr Optimistic,
Think we have to assume that, in the conventional notation: #1 = L/H and #2 = R/H. It would be very unkind of the BEA to label them otherwise. (Even if, in Phase 4, the R/H eng had been found first!)
RR_NDB,
Re the THS, I think you make a very strong point about the tank and its possible buoyancy. Maybe it has even washed ashore somewhere...
However, I seem to remember posting that, just as
tubby linton says, its tank would have been full of fuel. But the S.G. of the fuel is only 0.8.