It has been awhile since I disassembled a Colt replica---I forgot about that HandSpring.
My Ruger is quite different. It has the typical Hand but it uses a Plunger with a HandSpring attached that applies force to the Hand.
The HandSpring/Plunger is inserted in the back side of the Frame with plunger end inserted first and the spring protruding out the back. When the brass Grip is installed, it compresses the HandSpring.
Very interesting. There is a youtube somewhere that makes a similar system as an alteration using simple shop techniques for other revolvers. Requires precise drilling and tapping. Beyond my skills, though.