I have just been reviewing the information I have deduced from my CQ6230A-1 lathe and compiled this useful(?) table.
Here the quick change gearbox settings sorted for ratio:
Starting with the finest, i.e. slowest feed rate..
B5
B1
C5
D5
C1
B4
D1
A5
B3
C4
A1
D3
D2
E1
A4
A3
E4
E2
There are a few duplicates which I skipped.