Some how Widewing, I knew you'd know it.
There was an article about this plane that said that the visual strobo-flashing effect of the contra-rotating props caused pilot nausea and that it was not enjoyable to fly for more than an hour or so, even though this plane had a very long range. I believe that was also part of the reason that it was not produced, even though it compared favorably to the AD 1 Skyraider.
Regards.
Cement