280z strut rebuild

As I dig into ball joints, I look at correcting a leaking strut. I prefer to keep things stock, and assuming its not already been replace with a gas charged cartridge, does anyone have exp with rebuilding the stock setup? the damping seems fine to me as is, so I presume its ok only needing a seal to stop the oil loss. If so from looking at the FSM there is reference to an "oil  seal" and an "o ring". Both these seem to have something to do with keeping the oil in the strut.