Well, according to this (the "theory" part) http://originaltrilogy.com/forum/topic.cfm/THX-1138-preservations-Italian-Cut-available-see-1st-post/post/665567/#TopicPost665567

Lucas' ver.1 ver.1.WB ver.1 ver.2 ver.3
THX1138 1970 1971 1978 1983 2004

where:
version 1 1970 = Lucas' original (un-released)
version 1.WB 1971 = Warner Bros' re-edit (shorter) (released theater)
version 1 1978 = Lucas' original (theater, TV [16mm])
version 2 1983 = Lucas' next edit (- SEN shots) (TV, home video [LD Beta VHS etc.])
version 3 2004 = Lucas' next edit (+ CG) (TV, home video [DVD])

So, only 35mm & 16mm film for theater & TV, printed from 1978 to 1982, would be of Lucas' original movie (original length, original SEN shots) -- his 1st Director's Cut (as he lately, redundantly calls it). :)

After watching those SEN shots, I can see why GL would remove them. The voice dubbing on them is poor -- it sounds like what it is, women voice actors dubbing for the children (standard practice). Also, when the 2nd child asks SEN his name, SEN looks at the 1st child and asks if he has a name. But the 1st child whispers in the 2nd child ear not to tell his name. Clearly, SEN's counter-question should have been directed at the 2nd child, who asked the original question. Cut those shots and the problems are fixed.