Intro (ext) 0:00-0:11
Verse 1 0:11-0:29
Verse 2 0:33-0:43
Middle 8 0:43-0:54
Verse 3 0:54-1:12
Solo (verse) 1:16-1:25
Middle 8 1:25-1:37
Verse 4 1:37-1:55
Comments: Another 2-part intro (as was heard in [6b] "A Taste Of Honey",  "Thank You Girl",  "Little Child", [14b] "Roll Over Beethoven",  "You Can't Do That", and [31b] "Matchbox",  "Baby's in Black", [38b] "Mr. Moonlight",  "I Feel Fine", [46e] "Honey Don't",  "Ticket to Ride",  "Run For Your Life",  "Norwegian Wood (This Bird Has Flown)",  "Day Tripper",  "If I Needed Someone",  "Tomorrow Never Knows",  "Love You To",  "Paperback Writer",  "Rain, and  "Taxman",  "I Want to Tell You",  "She Said She Said", and  "Sgt. Pepper's Lonely Hearts Club Band") in that the first thing heard is a rooster call, then the "music proper" begins. Although in this case, because the first part is a sound effect, "Good Morning Good Morning" is most similar to "Sgt. Pepper's Lonely Hearts Club Band", which also features a 2-part introduction where the first part is sound effects and the second part the music proper.
The solo replaces a verse (i.e. the accompanying instruments play as if it's a verse, but the solo is heard instead of lead vocals). This is something I have noticed quite a lot in Beatles music, but I have not kept track of which songs do so to this point. I will take the opportunity to start - perhaps that can be tomorrow's blog.
Each verse (counting the solo as a verse) is identical in meter and chord progression through the first four measures. Then in the fifth measure, verse 2 and the solo segue to the middle 8s ("Everybody knows there's nothing doing...", "People running 'round it's five o'clock...."), while verses 1, 3, and 4 continue an additional five measures before a two-measure extension that was heard in the introduction ("Good morning, good morning ...").
Counting the solo as a verse, then, the macro-scale formal layout of "Good Morning Good Morning" can be seen as five iterations of the verse, with each successive iteration alternating how long that verse lasts and how that verse concludes (i.e. with either an extension or a transition to the middle 8), as discussed in the previous paragraph. This creates a palindromic structure (and just the fifth Beatles song to do so to date, behind  "I'll Be Back",  "Strawberry Fields Forever",  "When I'm Sixty-Four", and  "Sgt. Pepper's Lonely Hearts Club Band"). A visual representation will undoubtedly help illustrate the concept. In the odd-numbered iterations (indicated in green), the verses are all nine measures long and are followed by two-measure extensions; in the even-numbered iterations (indicated in yellow), the verses are all four measures long and are followed by six-measure middle 8s. They are roughly equal in duration, with the odd-numbered verses (including the extensions) lasting a total of 45 beats, while the even-numbered verses (including the middle 8s) lasting a total of 42 beats. This approximate equality contributes to the palindromic balance.