I don't know much about the different sources used for the home video releases but this guy seems to have a pretty good collection of many of them.

I suppose if someone wanted to, they could email him more info about some of his tapes and discs. For instance, he didn't know that the 2008 boxset was basically the same discs as what was in the 2006 individual dvds.

what really interested me was that a UK vhs set from 1994 was labeled "Digitally Remastered" yet did not have the THX logo on them. What was that source?

I also believe there was a special vhs boxset in place of the Definitive Laserdisc that just had a different lightsaber color on the box. It also came with a bonus tape that had the 1993 extras. I think that was the Executor set and that was UK Pal but that is not pictured and I don't know if that's the same as the "Digitally Remastered" set.

I'm from the US so I only know that there were basically 2 identical THX certified laserdisc sets in 1993 and 95.