Well, it depends on what you mean by original. Very few of the lines of dialog in the final movie were recorded on set. In the case Beru, all her lines were dubbed. There is the 77 stereo and the 77 mono versions of Beru. The 77 stereo just sounds bad, but it has been the version used in every audio edit of the film except the 77 mono. The 77 mono currently exists in fan circles in two forms. A UK airing of Star Wars utilized the 77 mono mix and most of the restoration/preservation efforts have included that audio track. More recently, a 35mm print with the English mono audio mix has been found and so we now have two different copies. My initial listen indicates that the UK airing is better quality.
Some fan edits have sought to fix this. Andywan’s Revisited replaced the 77 stereo version with the 77 mono version. I have a draft mix that I use for my color correction tests where I did the same thing.
The 77 stero version of Beru’s lines sounds badly edited. The 77 mono version of her lines sounds much better. Far more polished and what you expect from an Oscar award winning sound mix. For the 2011 blu-ray, they went back to all the original elements and still chose the 77 stereo takes and edits instead of the 77 mono takes and edits. I was very disappointed.
The 77 mono mix has several other significant changes. It has the Threepio tractor beam line (which reappeared in the 85 mix and then was absent in the 93 mix, but was back for the SE and has since remained), it has a different pacing when Luke, Ben and the droids confront the stormtroopers (which they added back later for the SE), a different take of the line when the stormtroopser are searching Mos Eisley and knock on the door Threepio and R2 are hiding behind, a different take of the line when it is reported to Tarkin that the Princess has escaped. It has lots of other differences, but most of the others have made their way into later edits. Most of the small things found their way into the 93 edit. Pretty much everything except the alternate dialog has been included in the blu-ray. I think the blu-ray uses all the 1977 stereo dialog and includes all the 1977 mono effects sounds (plus all the SE changes). Ben Burt claimed that some of the differences were because of the quality of the original recordings, but I don’t buy it.