I also very much enjoy how the band don't rush
the outro is probably climatic
Key = G major

this recording is from the Definitive Collection - Otis Redding WEA 1992
form of the tune could be looked at as 8 bar phrases or 16 bar sections where 13-16 alternate/differ.
I have put it into 8 bar chunks
(4 bar horn intro)
section 1
/G maj / E m / A m ? D7 / G maj / F maj / E m / E m /
look at bar 6

section 2 / Am / Am / D7 / D7 / Bm / Bb / Am / D7
again, look at the 6th bar of this section.
section 3 is the same as section 1
section 4
/Am / Am / D7 / D7 / G maj / C maj / G maj / G maj /
bridge is these 16 bars
C / C / Bm / Bm / Em / Em / Am / Am / C / C / Bm / Bm / Am / Am / Am / D7 /
next 8 bar section is the same as section 1 and 3
last section before unison outro goodness is
/Am / Am / D7 / D7 / Bm / Bm / E m / Em /
outro starts with A, up a tone to B then chromatic to lead into Gmaj / F / Em / Em /
this is a great tune to hear how a good band can make a good vocal great.