I flew on Concorde in 1990, and was an Air France owned plane. This has always made me wonder - how do I find out if the one that crashed a few years ago was the actual one I had flown on. I know Air France had 7 Concordes at the time I flew on it. Any help would be most welcome

Here's a link.
Air France Flight 4590 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Air_France_Flight_4590)

And here is a link to the official report

http://www.bea.aero/docspa/2000/f-sc000725a/pdf/f-sc000725a.pdf

They rotate aircraft for maintenance. I suspect you would have to ask Air France if they have the aircraft serial number (or whatever other identifier they used in their records) for that flight number on that day. I doubt they will provide the information, but it doesn't hurt to ask.