Most Colt double action revolvers use the over 100yr old 'long action' with V mainspring. There are different sizes , if you will , for the various size revolvers. Large for the New Service , med for the original .357 & Trooper , Python , Official Police. Smaller for the Detective Special , Diamondback , Police Positive.
The parts are complicated and complex to make and fit. It's probably easier to ruin a factory action than improve it unless you really know what you're doing.
The parts also don't lend themselves well to modern manufacturing methods either, require hand fitting/timing , thus are very expensive.
The Mk.III and Mk.V lockworks in the Troopers , Lawman , King Cobra and Anaconda , uses modern action design with coil springs. Much easier to tiime and fit.
The Mk.III originally was gonna use sintered metal parts. Powdered metal is put into a mold and heated till it all fuses together. They didn't hold up.
To be fair , it's not the same as the MIM parts S&W uses.
The original Colt .357 circa.1954 (shown below) has the same frame and lockworks as the Python.
The story was that the action of each Python received up to 4 hours of hand tuning and polishing
