Hatter096

I'm trying to get my P11 up and running, but among all the odd things things I keep finding this is by far the strangest so far. Today I took the fuel pump off the engine to see if anything from it was salvageable for rebuilding the one from the trunk, and as I pull it out of the engine I see a brass or copper nut on the rocker arm. So I'm curious what this is for and should I keep it for the "new" pump?