https://support.cessna.com/custsupt/...df?as_id=22175
During 1992 Cessna modified a number of aircraft to help prevent the mis-fueling issue.
This was coupled with reducing the size of Avgas fuel nozzles to prevent Avtur nozzles entering the tank.
Ironically the one aircraft I encountered that had the mod incorporated was reported as being unable to reach normal rpm in flight. It flew to Milan over the alps on a regular basis. After investigation we recovered a reel of masking tape that had been left in the tank during the mod with all the adhesive washed off and gathering on the fuel filter. Very lucky man to survive the flight. The whole filter looked as if it was covered in snot. As soon as the fuel evaporated the glue went hard. Cleaning out the tanks(wet wings) which had to be done with fuel in them in the summer heat was an appalling job never to be forgotten and bloody dangerous as well.