Another well made chapter. Perhaps some of the fight could have been avoided if Severus had simply explained to Remus, (the Snape Black feud would likely keep Sirius from listening, on principle alone.) I have often thought that as the horcruxes were created with a sacrifice, they would have to be destroyed int eh same manner. The diary had the death of the Basilisk in canon,(and the loss of Dumbledore's arm in book sux, to destroy the ring.) while here you have the locket being destroyed along with whatever spirit that resided n the locket. The earlier horcruxes would likely be the easiest to destroy, as Riddle had not yet reached his power.
Harry as peacemaker is a bit of a reach but you've pulled it off well. He's still Dudley Do-Right but he seems a bit more human.
As always, I eagerly await the next page of 'Hindsight'. Alorkin