I bought mine at the local sewing shop, they call them "modeling pins" there.
They cost as good as nothing (I think I paid like 1 Euro's for 20 of them) but they are a bit thicker than the ones from Victorinox, so I always have to use a bit of force the first time I insert them, but after that they fit great.
If I were you I would go to a sewing shop with your SAK and show them the pin and see what they have, and try to fit them in your SAK. That's how I found mine.
P.S. The look on the face of the woman behind the counter when I took my SAK out of my pocket was priceless
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