Jmann used to have some good pics posted here of his armorers chest with tray and most parts.
I can't find them now. They should still be here somewhere.
A picture and parts list can be found in the Colt Automatic Machine Guns and Rifles book that is available as a reprint.
I have one like yours, missing the tray.
That wooden ammo box is one of two types and is larger than the parts box, the other ammo box is not designed to be fired while closed and is the same size as the armorers chest.