Canterbury Cathedral - Cent
The chest is inside Canterbury Cathedral.
You can get inside by climbing a scaffolding from the outside and climb into an open window.
From this side on the second floor, you can shoot the barricade from the door on the other side.
Run to the other side, open the door and take the staircase down to the ground floor.
Here shoot down the chandelier to get access to the chest.
Quatford - Sciropescire
The entrance point is in the northwestern part of Quatford.
At the waterside, there is a boat full of oil jars standing right next to a weak wall (stone barricade).
Shoot one of the jars to open up the passage.
Then go all the way in. You will have to destroy a wooden wall and move a big stone out / towards you.
Then you can open up the chest.
Beamasfield - Cent
The chest is inside an open house with 3 entrance doors.
It requires 2 keys that you can get inside the camp.
1 - South of the chest location inside a house. You can get in through the window.
2 - In the logging camp building northwest of the chest location.
Wenlocan Outpost - Sciropescire
Inside Wenlocan Outpost, at ground level, there is a small cave.
Inside the cave you can move away a big stone to get into a small room.
The Armor Chest is in here.
Dover Fortress - Cent
The chest is near the docks. There is a weak wall / stone barricade on the floor that you can break.
There are some oil jars near the docks, not far.
Throw one there, get down, smash the wooden wall and the chest is yours.