I've got the original "close the blast doors" line in addition to all Beru's lines from the mono version of the film on the "Story of Star Wars" LP. Very good sound quality. The Special Editon version of the blastdoors line was re-recorded for some bizarre reason - maybe they lost the original master for the voice on this? I have a high quality record deck and can send you these if you'd like on a CD as WAV files. You could then splice these into the NTSC version of your DVD's. They'de have to speed up by 4% for PAL versions I believe.
PM me if your interested.
Cheers!
- John