Since I am talking about a half hour show it’s probably best to just start a new DV project. Import the 720p AVI file into the DV project resize it to fit 4:3 and render out an SD DV file. That file can then be sent to a DV deck via the normal procedure.
I’m just looking for a way to avoid spending all the time re-rendering after resizing the video for an entire half hour show. I’ll have to do a test and see how long that will take. I do have a dual 3.0 Xeon but it takes a long time to do this with even short clips.