Hi GRAMPS,
Basically the parts replaced are all of the internal action parts but the new model pawl you have in the gun is the same and now fitted to your gun so I would use that one.
hammer.
trigger (the retrofit trigger you have can be used by cutting off the transfer bar extension and the hump on the back for the return plunger) & trigger spring/plunger (but your spring/plunger is the same).
cylinder latch and spring (your spring is the same).
cylinder pin (not absolutely needed, just to be correct but the retrofit pin works fine).
Pawl (but see above) and plunger/spring (but the retrofit is the same).
The hammer is the key part if that's all you can find and even a large frame hammer will work, just shorten the top slightly where if it interferes with the rear sight. You can even use an OM super blackhawk target hammer. The cyl latch must be replaced with the old model but available new from Brownell's @ $4.99, part # 780-000-128AD.
You can also buy a Powers Custom new model hammer that has the 1/2 cock notch but no safety notch (useless anyway) that will work with slight modification at $ 118.67 part # 713-000-040AD. A little pricey but can also be found used on this forum. You can even get a Bisley hammer but a little pricier at $129.95.
You'll need very slight modifications of the Powers hammers to work:
trim the top as mentioned above,
enlarge the pin hole for your screw about .010" and
remove the overhang at the top right of the hammers shown here:
