copper washers

I have never seen copper washers or washers of any kind on the atmospheric side.
I have never needed to remove the studs,so have no idea what may or may not be inside the banjo.
But this one thing I know; I would not use them in either location. I would loc-tite the studs into the banjo, and use a proper gasket. NO RTV or silicon. Its a PITA to remove every time I go to swap pumpkins. I have never had those oem studs leak. Im not saying it cant happen.