I don't know about Taurus replacement parts but replacement parts are readily available for S&Ws. Numrich and Brownells are two places to check if you think you have a problem with a part. A bent pin would I think require a gunsmith, but would interfere with DA as well so I doubt if that's an issue.
Also ensure that you got the hammer block (looks like a miniature skeleton key, see below) back in place correctly last time you took it apart. On a S&W, it needs to be slid all the way UP on the post with the little flag on the end pointed into the revolver before the side plate is pressed back on. I have no idea if a problem with that could cause your symptoms.
