I’m sure the NSA doesn’t want to transfer a recording that might contain elements they still want to redact to any old outside firm, especially not one outside the U.S. as is your example. In the end I suspect this probably isn’t the only 1-inch open reel tape they would want to transfer to newer media. They would probably want to either bring a unit in-house or go to a facility where they can thoroughly vet the equipment and staff and basically take control for the duration of the project.