Interesting information on the Hurricane landing light:
"Walking clockwise around the aircraft, there is nothing remarkable about preflight of the wing, until arriving at the landing light. The first time I saw it, I thought the mounting was broken, but upon closer inspection, I realized
it moves! Some designer went to a lot of trouble with this item. In the original airplane, the landing lights were used one at a time, controlled by
a three-position switch. A "dipping lever" adjusted the aim, and a knurled knob locked the lever in place. Loosening the knob would allow the spring-loaded lever to move to the up position."
From:
http://www.warmkessel.com/jr/flying/td/jd/73.jsp
.