A Burglar Who Finds a Masterpiece
Returning the artefacts should happen and does not settle the account. You can send the manuscripts back; you cannot send back the six centuries of practice that would let someone extend the argument in them.
The Rosetta Stone was found by French soldiers in 1799, taken by the British in 1801 under the terms of a military surrender, and has been in London ever since.
Egypt has been asking for it back for decades. The British Museum has declined, on grounds that shift with each request: it is better preserved here, it belongs to the world, returning it would set a precedent.
The stone was taken without consent, from a colonised people, by a military power with no legal or moral claim to it. That it later turned out to be the key to an entire written language does not change the character of the taking.
A burglar who steals a painting and later discovers it is a masterpiece is still a burglar.
But the stone is a symbol, and symbols can be a distraction. The repatriation argument is the easy part of this, and it is not the part that did the lasting damage.