Aftermarket Canards

Today I learnt that some Mirage III variants were fitted with fixed canards.

I’m no aerodynamicist but I’m surprised that this sort of thing – fitting an existing airframe design with canards – actually works. Obviously the poster-child for this canards-as-optional-extra thing is the Su-30, but as I recall there was also an F-15 technology demonstrator with canards. Have there been any other instances of the practice, successful or otherwise?