Hi David,
Just to let you know that the Rover 100 and Metro door mechanisms are identical. I have Cd's for both cars and had to check them because I need a new striker and needed the partnumber. The pics for the Metro and Rover 100 are identical.
Off side door (that's the left I presume):
Metro: door latch EAM6035 or FQJ10055 (last one also mentioned for the Rover 100)
Cheers, Hans