Mechanism of the 1849 Revolver

To disassembly the lock, we need to first remove the grip. The one-piece grip is held in place by the back grip strap. There are two screws at the top and one underneath.
Once the strap is off, we can see the traces of the original silver plating where the strap is protected by the wood of the grip.
The grip itself is varnished walnut.
The relic revolver is missing its mainspring. Here is the reproduction disassembled to this point. The mainspring is a thick leaf spring that is held at the bottom of the grip frame by a screw. The roller bearing of the hammer rides on the spring.
Back to our historic example. The hammer screw is the rearmost action screw. It's been removed and the hammer removed. Notice the two notches in the bottom of the hammer.
Here's the roller bearing pinned into the bottom of the hammer.
Here's a close-up of the hammer from the side. Notice the complex geometry. It will make more sense when we have the other parts out and can explore how they relate to one another.
Next we take off the lower grip frame. I've got the hammer turned over left-to-right in this picture to show the more interesting side.
Looking at the bottom of the frame, we see a large screw on the left. This should be holding down the action spring, but it's missing. Moving rightwards there is a black bar that is the bottom of the cylinder bolt. Further right is the trigger.
Here's how it looks with all the pieces in place. This is the reproduction gun. You can see that the spring has two leaves, one for the trigger and one for the bolt.
Looking at the top of the frame, we see the dark rectangle of the cylinder bolt peeking through the frame. When the gun is cocked and ready to fire, the bolt moves upwards and engages the cylinder's bolt notches to lock the cylinder in place. If the cylinder is not precisely aligned with the barrel, we have, at best, a spray of lead shavings or droplets coming back at us, as well as a shot that has no accuracy. At worst, well...
Next, we remove the trigger screw. I've turned the hammer back around to point the proper direction. The trigger has the sear at its top. This is the part that engages the notches in the hammer, as we will soon see.
This shows the relationship between the sear and the hammer when the hammer is fully cocked. A pull backwards on the trigger slips the sear from the notch and lets the hammer slam forward as the mainspring applies force to the roller bearing.
Looking into the frame, we still see the bolt in place. Notice that there are two thin arms to the bolt that extend into the hammer cavity. These work with the cut-away area of the hammer to coordinate the action of the bolt with that of the hammer.
The bolt screw is the third action screw. Having now removed it, along with the action spring screw, we get a clear view of the bolt.
Here's another perspective on the bolt.