There is a Ferrari-looking air-scoop behind the cockpit of the I-153 and most of the Stearman planes too.
What is that?
The F1 air-scoop / airbox is well clear of the driver's head to feed air into the engine (the airbox itself is shaped so that each cylinder gets equal share of air).
In your 3-view diagram, that's a streamlined headrest for drag reduction.
Googling photographs makes it clear, unlike that line drawing.
(Source) Click to view.