The original U.S. DVD had the theatrical cut, with DD 2.0 mono sound, I'm sure the transition could be easily obtained from that.

Another source from which the English theatrical mono audio could be obtained would be the original VHS/Beta releases. Since Beta Hi-fi supposedly sounded superior to VHS Hi-fi, I'd go with Beta...and speak of the devil, look what I found on eBay:

http://www.ebay.com/itm/Beta-Monty-Python-and-Holy-Grail-/320885851436?pt=VHS&hash=item4ab649852c

Buy It Now for $2.99? Sounds like a steal, especially for a Beta...

Also, I think my memory may have been playing tricks on me. The 35mm print I saw in 2004 (not 2003, as I first recalled) apparently DID have the "Get on with it" scene - some blogger back in '04 mentioned it being a "slightly longer edit". Also, I think I was wrong that it was open matte - it was probably 1.66:1, since I think it was actually shot hard-matted at that ratio (all the full-frame releases were cropped). My memory may have gotten mixed up because the Paramount's screen is Academy ratio.

Either way, it didn't have Dentist on the Job at the start, or anything before the credits. And it retained the "Mønti Pythøn ik den Høli Gräilen" subtitle that was missing from the 2001 DVD - remember, this was before the 2006 DVD that corrected the fault in the subtitles, for which someone was hopefully sacked. :)