You folks in Finland have Ebay? That'd be my bet, although shipping for a wheel won't be cheap. Anyway, I imagine that if it's hard to find a wheel in your neigborhood, finding cones for a Gipiemme hub will be just about impossible. I live in a very good area for vintage stuff, and I haven't the slightest idea where to find Gipiemme spares. Again, Ebay may well be your best -- not to say only -- bet.

Good luck!