I love this footage so very much. In fact, I downright treasure it!
The only thing in a similar (albeit entirely hypothetical) vein I think I could ever appreciate more would be film of the Beatles recording "Strawberry Fields Forever" in Abbey Road, but that's neither here nor there.
From where I stand, for the purposes of the Beach Boys, the uncovering of these particular moving pictures was tantamount to unearthing the Holy Grail. Bonus points for the way in which the band utilized the footage during the live renditions of "Good Vibrations" on the C50 tour, as well.
Not that anyone asked, but as a personal aside, Andrew, I have to say that I really like this side of you - the fan coming out of you. It's much more endearing than that 'crotchety old man with a hard-on for correcting people' act you like to put on.
Yes, you're much more charming this way, methinks.