Here is a better view of the brassware. There are no set screws in the wheels and gears. Until 1912, a spring clip with a tongue was used. The tongue projected into a small groove in the hole of the wheel to prevent turning. This acted like a key, although there was no groove in the axle (the earliest parts did have a groove in the axle, but this feature had disappeared by 1909). Set screws were introduced in 1913, although some parts did have set screws in late 1912.
In the compartment with the small parts box, a small key is visible. This is the key for the lock on the box. The key is resting on a length of chain; this part was supplied only until 1914. It is not like the later sprocket chain.