These British pinfire revolvers are very rare and there is really not a lot known about them. It follows Adam’s patented pistol design from 1851 and was likely made in the late 1850s.
One of the main concepts of this revolver that differentiates it from others is that it was made to be very strong by having the barrel and frame machined out of a single piece of forged steel.
The original percussion version was one of the first self-cocking revolvers. This pinfire version works in both that double-action method as well as single action.
All components of this revolver are present including the loading gate and ejector rod. And everything works flawlessly and is super crisp.
The case appears to have been made for this particular revolver but I have no idea if it originally came with the gun. It has an ornate hinged box to store cartridges. There is also an early 20th century oil gun in the bottom cavity.
Here is a video of it.