This production restored much of the original licensed version of the show. Elements of the original version that were in this production included:
The high school scenes at the beginning and end of the show. This included "The Hills of Tomorrow," which was sung complete only in the final scene, as in the original Broadway production. (The original Broadway cast recording is a bit misleading on this, with the song sung complete in both places.)
“Rich and Happy" was the song in the 1979 scene, rather than “That Frank” from the revision.
There were separate scenes in 1975 (Polo Lounge) and 1973 (television studio). The revision combines (and largely rewrites) the 1975 and 1973 scenes into one scene set in 1973.
As in the original Broadway production, this production had a separate actor as "Older Frank" in the opening and final scenes.
Somewhat oddly, the Donmar production included "Growing Up" from the revision, but only in the first act. Gussie's "pre-prise" in Act Two wasn't included.
In addition to "Growing Up," there were some elements from the revision. For example, Gussie was a performer and the star of Musical Husbands (Frank and Charley's first Broadway musical), as in the revision, but her performance of "Good Thing Going" at the beginning of Act Two was not included. "It's a Hit!" included Beth, as in the revision. (This element of the revision was actually a return to the way the song was originally conceived and the way it was performed in early previews of the original production.)
In some scenes, the dialogue came completely or largely from the original version, while in others it came either completely or in part from the revision.
After the production closed, Sondheim said that he and Furth didn't know about what the production intended to do textually until rehearsals were under way and by then it was too late to make them switch to the revised version. (Read further for Sondheim's complete statement.)
Contradicting this to at least some degree is the following passage from an article in the Fall 2000 issue of The Sondheim Review.
"Will there be changes in the prodution?
"Sondheim told TSR that [Michael] Grandage has asked that the graduation scene be reinstated, 'with a difference.'
"'We'll try it in previews and see if it works,' he said."
Despite the production's success with the critics, which included winning the Olivier Award for Best Musical, Sondheim said, in a a Times Talk interview with Anthony Tommasini on March 26, 2001, that he and Furth would never allow anything like that to happen:
“The problem was that due to a misunderstanding, George Furth and I didn’t know that the version they were doing was the original version, not the revised one. I really liked what we spent years revising, and we would have stopped them if we had known. But we only found out when they were already in rehearsal.”
Given that the production started previews on Dec. 1, 2000, this appears to at least partly contradict Sondheim's earlier statement to The Sondheim Review. The Fall issues of The Sondheim Review have usually gone to press and even been delivered to subscribers before the Donmar production probably would have started rehearsals.
More puzzling still is that Sondheim later wrote in Finishing the Hat that the Donmar production winning the Olivier for best musical vindicated all the work that he and Furth had done revising on the show.
Adding further confusion is the following statement that Julian Ovenden made in an April 2013 interview:
"[M]y second job was actually playing Franklin Shepard in MERRILY WE ROLL ALONG at the Donmar and being directed by Michael Grandage in it. As you may know, Steve was pretty heavily involved with that production, actually, because we went back to the original version, which hadn't been tried out for a while."