Anyone know where these carbs can be purchased new besides MSA (who doesn't sell Mikuni's)? Surprisingly, after much searching, I was unable to find a place to buy 'em. Any help?

Try:

www.piercemanifolds.com

Another choice....

I haven't done business with them, but they do seem to have a lot of Mikuni parts.....

http://www.wolfcreekracing.com/classified.htm

Thanks guys! Those are great sites. Found what I was looking for. Watch out!