Back to the original question(s):
1) I can't find a link to the story, but perhaps a year (or so) ago there was an incident in which a would-be robber of a convenience store was killed by a customer who was carrying an Italian reproduction cowboy revolver. The reason it sticks in memory is that the customer hit the floor during the shootout and bent the trigger guard on his pistol so that the trigger was inoperative. He finished the fight by (as related in the article) slip-firing the gun. I'd call that a success story, but I don't know if the customer was carrying concealed.
2) I own a couple of single action revolvers, but I have never attempted to carry one concealed so I can't offer any advice in that regard.