OK, I got the TB spring to ride on the grooves, but it hasn't solved the issue. Seems to be an issue with the hammer as noted in post #1.
When the hammer is completely forward, the DA will not reset:
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However, when I move the hammer slightly back, the DA resets (you can see the tiny gap):
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At this point I am at a loss. Why wont the DA reset when the hammer is totally forward? Perhaps something to do with the disconnector that came with the RRK? Unless my timing is truly off, and the hammer isn't supposed to go that far forward, thereby preventing the reset...