If I remember correctly, the R2 mockumentary is on the episode II bonus disc.
I have a DVD with that “The Story of Star Wars” thing, but it’s only the summarized plots which pretty much aren’t worth watching, I didn’t even know there was a doc that goes with it?
There’s also the Musical Journey disc that came with the ROTS soundtrack, it’s not really a documentary, but it’s music videos for the whole saga with introductions by Ian McDiarmid.
The “Story of Star Wars” DVD was a compilation of the first 2 discs from the Hasbro toy. The third disc wasn’t included at all, but I was wondering if the videos were exclusive or if they were featured on the movies’ releases on DVD.
I got mine as a bonus DVD with the (I believe it was) Walmart release of ROTS. No idea if it was ever available any other way.