Porco Rosso.....
It would be a bit borderline as to whether fitment of a CVR was mandatory at that time in that area. The UK, for example, did not make it mandatory until quite a while after the Trident crash at Staines in 1972. So given the time scale...Investigation-Public enquiry-report-recommendations, 1975 makes it a bit unlikely.
As in the case of Stardust, the authorities are obliged to mount a full investigation, even after all these years. The cold would make Post Mortems feasible and the wreckage has been undisturbed all these years, so i think at least a probable cause would be on the cards. I think, given the situation, that CFIT may have claimed another victim 27 years on, but let's not pre-empt the enquriy (He said swiftly) Hijacking was all the rage way back when wasn't it.??