Take a look at this sticky: https://tw200forum.com/index.php?/top...ick-start-kit/
Remember a new gasket for the case cover.
#10 on your first picture is a seal. Cheap insurance to get a new one.
#13 on your second picture is a washer with locking tabs, a new one will insure the tabs can be bent back in place without breaking...a picture of this is below...