Before you start, get the latest Gordian Knot rippack from Doom9.
Do this:
1) Open up DVD Decrypter. Change mode to IFO.
2) demux the audio and the english ac3 file as separate streams. Unless you're doing something custom to the AC3 file (as I did) just leave it alone and re-mux it with the changed file.
3) Using the latest rippack of Gordian Knot, launch dgindex.
4) File/Open/the M2V file you demuxed. Click OK.
5) Save the D2V file. Go do situps for about five minutes. When it is done saving:
6) Launch the actual Gordian Knot program. Click the "open" button in the lower left corner. Point it to the .D2V file you created above.
7) Click "Save and Encode" ... this will bring up another window ... just hit SAVE (not Save & Encode) on this window. This will create an AVS file. That's just a simple text file that you'll edit with notepad. Close Gordian Knot.
8) Open the AVS file. Change the line with the crop command to this:
crop(0,0,720,480)
and change the line with the Lanczos resize to this:
Lanczos4Resize(720, 480)
Save the file.
9) Launch TMPGEnc. Select at 16:9 NTSC project. Load the modified .AVS file into it. Set the Average Video Bitrate to 8000. We'll recompress after muxing, but this will ensure the best quality recompress from the source file to the anamorphic file. This will create a new M2V file and a WAV file. The wave file will be empty junk you'll delete when you're done.
Let this run overnight.
10) Load the new M2V file, the original AC3 file, the chapter points, and the subtitles (see my earlier post for the ones from ANH so you don't have to rip them) into DVDLab Pro. I think you know what to do from here. If the result is larger than a DVD-DL, you can use Nero to recompress to DL or SL. With the AC3, you may not need to recompress.
I know you can do this. Let me know if you have any questions about any of these specifics.