The George Harrison song "Too Much" started life as a backing track recorded in four takes on May 25, 1967 at De Lane Lea Studios in London. The instruments sued were mainly drums, bass, guitar and organ. The backing instrument were all put onto one track; the second track featuring George's main vocals along with the backing from John and Paul. while percussion (tambourine, cowbell) were put on track three.
On June 02 in the same location, George Harrison saw the overdubs for trumpets and bass clarinet. Once again, there didn't seem to be a score waiting for the musicians to follow so - like "Magical Mystery Tour" - there must have been a lot of experimentation and improvisation until the desired result was accomplished.
The first mixes completed were conducted at De Lane Lea Studios on October 12 1967 - a mono mix and a stereo mix were finished and ready but the song lasted over eight minutes at this point ! The mono mix was copied at EMI Studios on November 15 1967 and was given to the film producers. The producers were weary of the long time length of the song and (like some of the other songs on the film soundtrack) was heavily edited by only including the intro, first verse, second chorus, a trumpet break before skipping to the fourth verse, the fifth chorus and the beginning of the long ending chorus. Whew! Quite the chop.
When it came time to mix for the commercial LP, the original De Lane Lea Studios tape was copied to an EMI Studios tape and a new series of mono and stereo mixes were conducted in late October 1967. This time the mono/stereo mixes would use a different editing from the film soundtrack. The third and fourth verses were removed and there was an early fade out produced. The mono mix would not be released until the 2009 mono masters (EMI/Apple Double CD). The stereo mix would appear on the Apple LP/CD "Yellow Submarine".
Finally, the stereo mix on the EMI/Apple LP/CD "Yellow Submarine Songtrack" contains pretty much the same stereo mix although the organ is isolated in the left channel.
The complete eight minute version of the song can be found on various bootlegs including the LP "Arrive without Travelling, the CDs "Arrive Without Aging" and "The Lost Pepperland Reel".
I've included a youtube link to the edited mono mix: