re: The Concorde example
I don't think Concorde helps you much. Yes, it resumed flying, but only for a brief period of time and with lots of attention to outstanding safety issues. The immediate response was to get it flying again, but it only took a brief time of looking at how much still remained, and how non-cost effective continued operations with those safety fixes would be (combined with growing O&M on an old system), and it was retired.