Honda Civic 1.8 and one of the CRV model in Malaysia market is install with R18A and R20A engine, which is also found in one of the Proton Perdana engine, their oil pump have 3 o-ring just like the red circle mark in above diagram, and you can watch where actually the o-ring situated in the physical oil pump as below photo.
It is not understand why the overhaul gasket kit didn't include this 3 o-ring in their content, where it need to be purchase separately, of course, at KP, we have the o-ring readily to serve your need.