My guess on your cylinder stop is that the split spring is broken, loose, or missing or the coil spring is missing or broken. The split spring is a rather complicated looking spring that aids in the hammer sliding under the cylinder stop. The coil spring keeps downward pressure on the cylinder stop. When the hammer is pulled back, it interacts with the split spring and forces the cylinder stop upward, releasing the cylinder to rotate. When the hammer passes the stop, the coil spring forces the stop against the cylinder as it runs across the top of the cylinder until it falls into the next slot on the cylinder. Make sure that the springs are working by lifting the cylinder stop to see if if snaps back down when released? You will have to remove the hinge pin in order to see the split spring. Springs may be available, but I have not seen any.
As for the hard hammer pull, take the stocks off and watch the mainspring as you pull the hammer back. Many guns are tinkered with and lengthening or shortening the strain screw is one of those things that can actually make the mainspring rub on the frame so look to make sure the main spring is free and clear of the frame when it is cocked.
The ejector rod knob is a two piece unit that was made by a member here. Jack First makes replacement knobs that are one piece that will also work on your revolver.
S&W 1896 .32 Hand Ejector extractor rod knob #830-328 – Jack First Inc.
Let me add another link. I found that Jack First also has the split spring.
S&W 1896 .32 Hand Ejector split spring #830-342 – Jack First Inc.
Reply back with any further observations.
