Sd33 diesel mq patrol 81 leaking in the injector area.

[BIGPATTYLOVER]

Hi everyone,
I have been having problems with diesel leaks around my injectors since my mechanic changed the main oil seal and big end bearings and conrod bearings recently.
Apparently there isn't a washer you can replace on them so he used emery paper to create a flat surface on the brass bit where the diesel goes in yet it still leaks, hoping for some one with a similar experience to help me out
THANKS
MICHAEL.