......The problem I am faced with is the original raw footage requires a A/V driver for the audio to work from a third party company that may no longer be in business....]
WalterB, it's more of the type of camera that was used that requires the special audio decoder software. It also came with it's own HD video drivers that installed into the computer's operating system. I need to spend time to look up the manufacturer to do an Internet search for compatible drivers. It was for an old Panasonic Professional HD camera from 10 years ago. As good as that camera was back then, a modern DSLR can give it a run for the money these days.
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You dodged the question without realising it
A type of camera gives a certain codec. In the end the file does not remember the camera, but it's codec
Codecs that required drivers in the past can be codecs that are supported natively by a lot of software today.
You might be able to convert the old footage to PreRes of DNxHD with software like PavTube.
(It is not free, but I sometimes use it when clients send me odd codecs or insanely large uncompressed screenrecordings.)