There is only one official recording of SBR and that’s the one from the 1980 live concert. So yes it’s the same. As YEF pointed out, there was a discussion about the deconstructed SBR video on one of these threads. Only then can a person tell that Don H filled in brief gaps during Glenn’s part, presumably b/c Glenn wasnt interested in coming back to the studio to dub in these parts himself. Normally I don’t think it’s obvious.
The ‘76 Seattle version is a bootleg and not an official release. Personally I wasn’t interested in downloading the whole Live album from iTunes, just the tracks I wanted. But if you don’t already have SBR, I would definitely suggest getting it b/c it’s such a classic display of Eagles harmonies (I have it already on GH 2).