There is a torrent out there for a This Is Spinal Tap Workprint, but the quality is pretty bad (vs. the DVD - I have no idea what the average Work Print quality is expected to be). Just type "workprint" into your favorite tracker - it's sure to show up.
Dr. No is there as well. Doesn't seem to be a commentary for the Fisher King anywhere though.
Just stumbled on a website called "listentoamovie" which allows people at work to listen to movies on their computer, and scrolling through the soundtracks, I found the Criterion versions of Goldfinger and From Russia commentaries.
Hope someone finds this helpful.