Image resolution poor, movie mostly hi rez stills

Hi --

Is it ok to post questions about FC Express? If so....

I've created a movie that is 98% stills (no effects, mostly png, ~2000 x 3000px) and some SD video footage.

Output resolution is poor (see below for processes and codecs used). It's definitely lower than 720 x 480, looks about 35% loss to me. I do have a screen grab if I knew how to post.

Early admission: I'm new to FCE (and just transitioning to Mac), so didn't know to set up timeline resolution to the target 720 x 480 output.


What I've tried--

1. QT conversion, set dimensions to NTSC 720 x 480, highest quality

2. New project, set timeline resolution to SD, copy and paste old movie project into new timeline, export using both QT conversion and QT movie

3. Apple intermediate codec 1080i, HD, then exporting using QT Pro, resized and highest quality

4. New project, set timeline to SD, copy and pasted old project into new timeline, exported using SD QT movie and QT conversion.

4. For comparison.....
New project, set timeline to SD, placed one png image into timeline. Exported using both QT movie and QT conversion. Opened all three movies in QT Player. Freeze-framed the same image in the old movie and the same image in the new movie(s). BIG difference in outcomes. Old = bad, new = good

Questions:

How can I rescue my old movie? (Any way to re-link to originals and re-render?)

What happened in my original effort? (less important question) Did I blow it when I didn't do easy set up for SD? Did I render images to death while making the movie?

Any help is deeply appreciated. 80 stills and intricate transitions later and the thought of re-doing everything is heartbreaking...

Thanks so much.

Gina