James, Funny you should ask about the Walker and that #%$#^& mainspring!! :cursing: I shot my new Whitneyville Dragoon yesterday and as you know it has the same mainspring setup as the Walker. I had a devil of a time getting the mainspring re-installed.
After several failed attempts I loosened the three screws holding the triggerguard in place. Only a few threads engaged in the frame, so the triggerguard was "dropped" away from the frame. Then I just squeezed the mainspring until the hook was under the hammer; then while holding everything in this position I hurried and tightened one of the rear screws of the triggerguard. The mainspring engaged the hammer and then I tightened the other two screws. It would have worked a lot better if I had three hands. And more muscle.
Several weeks ago someone posted on here how they installed a Walker mainspring but I can't remember exactly how they said they did it. But I THINK they used one of those plastic ties used for holding bundles of wiring together. They compressed the spring toward the front gripstrap, out of engagement with the hammer, then tied the compressed mainspring to the gripstrap/triggerguard with the plastic tie so that the spring stayed right with the triggerguard.
If that person reads this post maybe he will do humanity a kindness and repost his method because it sure seemed a lot simpler than what I struggled with.......and what you're obviously going thru! And I do hereby thank that ingenious individual in advance!!
Hope this helps...........
Dryball aka Ken