They have a contact here in the states.
IIRC, I've bought Rummo from Ernest Klein and Company in the past.
Ernest Klein and Company --> http://www.ernestklein.net/
Also, here's the Rummo pasta link --> http://www.pastarummo.com/
I'm guessing that the Manhattan Fairway(s) would carry it as well. Try them too.
I've seen Rummo in many places around town, including BuonItalia in Chelsea market. They don't always have it, though, so I'd call ahead before going there. I think I bought it in Faicco's on Bleecker, too. Of course, if Bklyn is more convenient for you, I suggest you call Faicco in Dyker Heights. The one place I know of that always has Rummo pasta is Casa della Mozzarella in the Bronx, but that is outside of your requested range. FWIW, that is where I've bought it the past couple of times, and couldn't swear to having seen it in Manhattan recently.
I have been trying to find a consistent source for Rummo for a couple years now. At the time of these initial posts- BuonItalia had not stocked Rummo for over a year I would say. The Bkn Fairway was the only Fairway that carried the Rummo. The Bowery Whole Foods had some at the intial opening but never ordered more . . .
Have you had any luck finding Rummo? I am tired of NOT having this pasta.