(Photos with red carpet background courtesy of Chris Lener)
 

This Alexander Henry was manufactured by the Westly-Richards Arms & Ammunition Company.  Literature I have seen indicates that they were also manufactured by Alexander Henry directly and by National Arms and Ammunition Co. (Birmingham).

The plunger at the end of the operating lever ahead of the trigger guard locks the lever
into place in the closed position.
 

Action open (above and below)

New South Wales, Australia