For any that are interested, I figured out a slightly different workflow from what I described before.
After exporting my 1080p DNxHD145 sequence (native), I run it thru Compressor, to convert to DVCPro50, NTSC, with a 4:3 crop. Very simple, VERY Fast. Takes about a minute to export the 4:00 mins from the AVID and less than a minute to run thru Compressor.
The graphics stay nice and crisp, which was a problem with my earlier version. The colors are bright, all in all a good workflow for this situation.