AFAIK there were two in 1980 and 1988....later ones (eg for the 50th anniversary of closure) were scuppered by the authorities
see in another learned place:
Croydon Airport 50th Anniversary Flypast
and with the help of our friends Google and Flickr and YouTube
1980
https://www.flickr.com/photos/duke_o...7626610439814/
slideshow version
https://www.flickr.com/photos/duke_o...10439814/show/
https://www.youtube.com/watch?v=T1P1ouSMFhc
1988
EDIT...the link to James Kightly's blog about the Spitfire at the Croydon 1988 airshow won't link ...Image Googling 'Croydon Airport 1988' brings up the pic [mixed with images of the Croydon goddess Kate Moss :-)]
https://www.google.co.uk/search?q=cr...ml%3B880%3B566