The locking circle is directly tied to the type of Sidewinder. Not aircraft to aircraft.
Photos, later documentation, weaponry documentation. If something was fitted with something at some stage, there is likely to be evidence of it.
According to the Etendard Manual it does not have CCIP but a crude form of bomb toss. So far we have yet to find any overriding information and thus cant give it CCIP it didn't actually have.