Is there any known or guessed quantity of He3 on asteroids or dead
comets? If an object has been orbitting for 4+ billion years, it
should have collected some from the solar wind. It seems that He3
would be easier to obtain from something like Eros than the Moon, if
it existed in similar density. If there was a supply, collecting and
separating He3 could be much simpler in the micro-G environment.

I did a quick Google and found little, but am wondering what you
think?

Josh