Its a combination of the 'TB' broadcasts your team used for your 97SE release, patched with the 'Gkar' broadcasts, which are pretty much frame complete but of a lesser quality. ROTJ also had to be patched with the official DVD in a few places due to the fact that every 1997 release is missing quite a few frames from what was deemed 'complete'. It was agreed that the official DVD's were frame-accurate to the 97SE when you excluded the '04 changes (Palpatine in TESB, Naboo appearing in ROTJ).
I'm almost certain the frame counts are accurate because of how easily it was to synchronise; position each reel correctly to the reference video and mixdown; no time-stretching or cutting the audio mid-reel was needed to make it fit.
My video sources have been included with the DTS-HD versions for the sake of having a visual reference to go with the audio, and they are by no means a preservation. I leave that sort of thing up to people who are much better at it.
The synch information is in a text file with the audio (and will be with the WAVs too), but is taken from this thread where it was discussed quite a while back.