Whoah. So now I have a new theory for why they swapped out the Castilian audio for the compactor scene in the GOUT.
There is scored music in this scene, for the Castilian Spanish audio, that AFAICT isn't in any other version of Star Wars anywhere ever, and was removed on the Blu-ray release. It sounds like part of the same piece that plays when R2 wakes up in the Sandcrawler and rolls through the menagerie of droids on the way to finding C-3PO.
I don't know exactly why this would make someone want to swap the audio out when they made the GOUT, but maybe they thought they had some sort of bastardized TV broadcast audio, and went back to their sources and found audio without this bit of the score. Since the Latino dub has been out of circulation so long, maybe they didn't even know there was a second Spanish dub, and that's what they got by mistake.
Anyway, I sure hope I can incorporate this into the Castilian GOUT audio. It's a little hissy, but the unique score definitely makes me want to try my best!
Then again, this VHS copy really is the sort of bastardized TV broadcast audio I mentioned. It does have the made-for-TV voiceover on the crawl after all, so it's not theatrically accurate in that respect. But would a TV version include such a slight alteration to the score? Seems farfetched to me.
Any ideas? Do you think this slightly different score was theatrical or not?