In 2003 a great book called "England Their England" came out which listed every player from outside of the British Isles to have played for each club.
At that time City had had 59 non-British Isles born players appear in their League team. This was the 2nd highest (Chelsea had had 64) and started with Bowman (Canada) in 1890s.
The book also listed each nationality and which players had appeared in the League. Obviously, since 2003 every team, particularly City has had considerably more overseas players. If I get chance I'll check the nations pre-2003 and see if we've got them all here.
The 59 players listed in 2003 did include some 'British' players born overseas such as Les McDowall & Steve Lomas.