Found them!! You are right, it does make it much, much simpler to install the spring....
(My pair is convertible for either inner or outer rings..)
Anyway, I couldn't resist tearing down both guns (once again) to see if I could understand the rebounding hammer and cylinder lock function. I think I finally see it..
Here is a close-up of the proper hammer sears.
The three "notches" left to right are: 1. the sear notch, 2. the safety notch, and 3. the rebound notch.
As the hammer is cocked, the trigger moves to the rear and the cylinder bolt is raised, locking the cylinder.
When the trigger nose comes off of the sear notch, the hammer falls and its inertia carries it past the mainspring equilibrium point allowing the firing pin to strike the primer.
The hammer is then immediately withdrawn to the rebound position by action of the mainspring. If the trigger is held back, the hammer can be manually "pushed" back into contact with the primer. When the trigger is released it only travels as far as the rebound notch and is held there and will not allow the hammer to move forward. It also doesn't allow the trigger to release the cylinder bolt, thereby keeping the cylinder locked. If the hammer is thumbed back to the safety notch the trigger is moved slightly forward thereby lowering the cylinder bolt and releasing the cylinder to rotate. The trigger is then captured and will not move in either direction until the hammer is cocked enough to free the trigger nose from the safety notch.
At least that how mine seems to work. The only thing I can't quite understand is why the cylinder is unlocked when the hammer is in the safety notch. Shouldn't there be some sort of indexing to keep the cylinder ready to bring up the next unfired chamber or was the design meant to have the gun carried in the rebound position with the safety notch being just that, a safety device in case of a cocked gun being dropped??
(I think both guns and myself will be relieved that we won't be disassembling again unless some new parts are found...)