Historical Air Traffic Control Recordings - 1960's


I am putting together an aviation history presentation for a training class I will be instructing. I have been scouring the web to no avail for any site that might contain historical air traffic control recordings from the 1960’s or earlier. I know of some hobbyists who record/retain ATC communications and I suspect that practice has existed for years.

I have come upon a gentleman who has an hour of recordings from MIA tower from 1972 and I am awaiting that promised MP3. With Braniff, Eastern, National, Pan Am, TWA, Southern, etc. etc., he tells me its a great hour of nostalgia. Although, ideally I would like to find some older data.

Neither NATCA nor the FAA has been able to provide any leads.

Has anyone ever come across such data? Any ideas or suggestions?

Thanks Folks,