Get the 7/8, stick it in a drill/drill press, spin it up, apply 80 grit sand paper till at desired diameter, buff, apply corrosion inhibitor and paint (thinly). Bam!
I know thats a little crass but it's cheap and it "will" work. Nissan stuff is always metric in my experience. In my opinion you may find it easier to pull the old pins of a S13/ most Nissan's and use them :>