Bonjour
PR.
Large turboprop aircraft back then
were equipped with CVR/FDR, but they were rather primitive compared to today's equipment. The FDR would have been the foil type that had about five or seven parameters, as I recall, and the CVR's were continuous loop tape with about thirty minutes of recording time. It would be a miracle if anything useful could be obtained after all this time. Of course, who knows maybe the cold would preserve the data.