i've got a NOS campy athena headset. I measured the cups and they're 30.2 mm, i measure the crown race and it's 26.4. Someone wanted to buy it off of me and they were asking if it was english or italian. How would i figure this out? i looked under sheldon and it would classify under ISO, but i don't know what the threads per square inch are.

here's a pic of the headset: