update
update
So after 5 minutes of intense blowing with the Giottos, I blew the piece of dirt off, but not before it left a trail of residue....What was a tiny spot of dirt is now a 3mm trail across the sensor. Oddly, I'm actually relieved that it blew off as I thought it might so how have been something more than dirt (like a scratch). I've got a 50mm elmar f2.8 that I mounted on this ( it says it's okay on ricoh's website) and if fits in the lens checker collapsed - but barely, so I was a little nervous I managed to damage something.
I guess I'd eventually have to get a sensor cleaning kit anyway, I just didn't expect it to be 3-4 days after I bought the unit. Thanks all for the advice.