Now that I rethink this, I am wrong.
704x480 is a valid pixel size, and the max rate is 9.8; although Encore will only allow you to pick up to 9.4 for the default transcode rate (which should not be applied to your timeline asset anyway).
I have not used rejig. I used videoredo in the past; but the point of such products is to keep the original transcoded as much as possible. So all this says is that the service agency put the content on disk at a high datarate, and at a very common size for earlier camera capture/transfer.
Have to think about this some more as to why Encore is not accepting the input.
I don't see this: Did you put just one of the original files in Encore? Does it say "do not transcode"?