I bought a broken Colt Agent myself and bought parts from Jack First, and I thought seriously that I could repair it. I had a merry time getting the spring and screw for the new hand in there (no space), and I was up and down finding the spring that got away a few times. I got it all back together and it just did not work.
It was rather frustrating. There were involved really under a dozen parts. The problem was: some parts needed special fitting and one could not see how they interacted, or what was going on, because they operated in two layers, and the problem was underneath the upper layer.
My friend's gunsmith cousin also had a go at it. He, too, failed. So I finally sent it to Cylinder& Slide. They fixed it and tuned it, and it works beautifully now.
