The interrupting ratings are in the attached .pdf (page 2 of Masterpact MP technical catalog 0631CT9501R11/9)
The difference between model numbers is the amperage and interrupting rating. See page 2 of Masterpact MP technical catalog 0631CT9501. This complete catalog can be found in the Schneider Electric Technical Library.
Model number prefix definition:
MP UL489 listed version labeled Merlin Gerin
MC ANSI/UL1066 version labeled Merlin Gerin
MS a Square D labeled version