Ours were much smaller, electrically driven, mounted firmly in the wing and aligned by the Armourer.
Mounting needed to be solid; when you got the 12 .303 Brownings all running on a Hurricane II, there was a LOT of vibration. With enough tracers, you could see the separate cones of fire.
I picked one up some years ago, showed it to my Dad. He wasn't interested; he had repaired too many with he was at No. 2 B&G and then with 133 Sq'n.