MB Air was erased by Find My iPhone; how can I find its location?

My MacBook Air was stolen in July 2012

It was running OS X 10.6.6 Snow Leopard

Find My iPhone was activated under Preferences'

On 28-January-2013 I was notified that the "Erase Mac" I had requested had activated and the MBA had been wiped

I was also notified that "Play Sound" had activated

I had sent a message via Find My iPhone to display a message with my phone number and a reward for the return of the MBA.

My Question: All my other devices, including this MBA, are showing a specific location on 'Find My iPhone'. But the MBA that was stolen and that was erased by Find My iPhone is not showing a location. I'd like to know how I can track down where it is now.

Note: I can see that the "new owner" has given the MBA a new name.