Oh, I understand - take a nice break, and come back later with fresh ears!
Yeah, leave the double-lighsaber-light-up, it's a mistake but I like it. And it's clearly part of the original mix.
Now, here's something I've never noticed before - I dunno if it's "new" to the 1980 mix, or if I'm just thick and never noticed. If someone could let me know if this appears on the 1985/1993 mix, I'd be very interested:
When Luke enters "The Cave" and meets Luke-Vader, right before Vader appears we hear splashing off-screen, then the sound of water sloshing, making it sound as if not-really-Vader is coming from inside a pond or something. I think it's kinda cool, but as I said, maybe it's always been there and I'm just thick.