I'm sorry but I really don't think there was any Lowry cleanup until 2004. From everything I've read, the 97 was a mostly photochemical restoration (bar the effects shots, of course) Even the wipes were redone optically.

I haven't seen or read anything that suggests that in 95-97, they ran the whole film through a computer, digitally scrubbed it and then outputted it to a new negative. The SE negative is a mash-up of the original camera negative from 77 and digitally re-comped effects shots.

According to The Secret History of Star Wars: http://secrethistoryofstarwars.com/savingstarwars.html

"The restoration of Star Wars began in 1995 and took the combined efforts of three companies: Pacific Titles, who handled optical printing, Lucasfilm, who organized the restoration and brought in ILM, and YCM Labs, who were responsible for color timing [...] It would have been far too cost prohibitive to scan and digitally restore the entire film at that time, so only the shots that were going to be enhanced with digital effects ended up in the computer."