it is NOT a Grateful Dead production (hey, neither is Woodstock...) and one of the main reasons the release was delayed and the result is so fragmentary is that the promoters, while they treated the performers like gods, stiffed the crew bigtime, with the results that the camera guys ran off with the reels. It's something of a miracle that this was rescued at all; as I understand it the reels that were salvaged represent about a third of what was shot.
This is, of course, an oversimplification. But it is simply inaccurate to assert that the footage is in the GD vaults or that Rhino Records has jack to do with the whole thing. It's not even in the Store. And, as asserted above, while the Canadian National Film Board may have a full set, the Grateful Dead sure don't.
Hell, the Dead don't even get top billing on this. And they sure didn't call the tune.
It's still great.