I understand that you want to preserve quality, but the numbers are confusing you a bit, I think. Just because the lossless AVI is 24GB doesn't mean that you need a similar size after encoding to a delivery format to have something that looks like a raw capture on the disc. After your current encoding is finished, try using a CRF of 16 (which is absolutely sufficient to make something look like the source) and let us know the file-size. I bet it will be something like 3GB.
It's just under 4.5gb without the black borders cropped away and it does look fine to me. I'm glad you guys educated me on this.
If you're keeping quality at a maximum, why not keep the audio as uncompressed PCM instead of encoding it to Dolby Digital? You should still be able to get a bitrate around 7Mbps with the 8GB limit of DVD9 if you really want to. Even 8Mbps seems quite high for 480i when encoding to h264/AVC, so you should easily manage the quality levels you're hoping for. ;)
I've synced it with the audio files from schorman13's project. I can easily release it uncompressed. It is around 1.2 gb if I remember right.
I really hope you'll consider still releasing unaltered 480p transfers as well. Based on what you said about leaving it unfiltered, if any other users hoped to make cleaning attempts on your transfers (with your permission and credit), it would be easier to work with something that has not been resized and is more representative of the true, raw form.
I believe I'm going to change from a blu-ray release to an mkv file release. It seems that most people interested in this would have the knowledge to demux and put it into whatever format they want anyway. If I understand right I could mux in the 720p and the 480p videostream and the uncompressed audio file into the same container file and it should all be about 12-13 gb. Since I'm upsizing to 720p now I will be denoising it but the 480p would be raw(as in no filtering).