Joe
The photo of the Perrins with the cocking leavers like yours does not show that the hammers can be cocked by a leaver under the trigger guard - which also locks/unlocks the action. It is fairly stiff to operate when both hammers have been released. I guess the next step was to use barrel cocking.
What a cracking gun you have - i also have a 14 bore - what do you use to feed it with?
John