The Louvre said the crown still had all its pieces, except for one of the eight golden eagles that adorned it.
It retains all 56 of its emeralds and all but 10 of its 1354 diamonds, the museum said.
It said an expert committee led by the museum’s president, Laurence des Cars, had been selected to supervise the restoration, which would be carried out by a qualified expert chosen in a competitive selection process.
Authorities have arrested all four alleged members of the heist crew but have not found the mastermind – or the remaining jewels.
The thieves made off with eight other items of jewellery, including a diamond-studded tiara that belonged to Eugenie, wife of Napoleon III.
-Agence France-Presse