Good work, good questions.
The C7 is a V of iv in Ab major. This is called a secondary or applied dominant.
After the IV chord in the last section, it's iv (four minor) to iii, to vii dim 7 of ii (an applied dim 7 chord, similar to a secondary dominant), to ii, V, I. The whole last section is in Ab major, with chromatic passing tones making the harmony interesting and less stable than the rest of the tune.
It is common practice to use Arabic numbers for scale degrees, and Roman numerals for chord qualities. Upper case Roman numerals are major, lower case minor.
Originally Posted by Basscat125
Bar 8 would be a c7(what key centre is this chord based around)
Bar 1-5 of C are a 6-2-5-1-4 in Abmajor
What are bars 6-8 of C?
bars9-11 of c are a 2-5-1 in Abmajor
Bar 12 is a 2-5 in Fmin
I am new to this sort of analysis so If this is wrong I just want everyone to be blunt..
p.s. imm transcribing some sweet ray brown stuff on this tune!