Technically, this IS available on DVD/Blu-ray, but...

I found the deluxe laserdisc box set of Snow White and the Seven Dwarfs for 10 bucks at a Half Price Books. I'm not sure if it has any extras missing from the DVD/BD releases, but I do know that it has a lossless version of the original mono mix, which is only at 192kbps on the current DVD/BD. It's only in CX analog (with the stereo remix on the digital track), but it is the only uncompressed version of the original sound mix ever released.

I definitely think this track needs a preservation. I'll send it to anyone who can capture it.