M201 toolbox / coffre
This is not a standard item of M201 equipment but clearly someone discovered that the crates in which practice rounds for a 105 mm howitzer had once been supplied made excellent storage boxes for pioneer tools (axe & shovel) when not mounted on the vehicle. Other examples from the same source indicate that these crates were used to store sets of tools for both trucks and jeeps. In the example below the 'J' signifies 'Jeep' and the set that were inside this crate obviously once belonged to M201 no. 8553 with the registration 285-1050. The jeep belonged to the Gendarmerie at Pithiviers so perhaps this was a Gendarmerie thing.
Thanks to Baz for letting me photograph this item from his collection.