Yeah mate, you're screwed. Worse than that, a couple of days prior a pair of F2 calipers and a MC went for under 30 bucks. That seller must think he hit paydirt!
Now I don't have access to EBay from my Defence Department computer, but did you get the whole front end with forks, triples front wheel, etc? (I imagine you did for 140 bucks?)
If you did you'll be able to make it work, no problemo. Cheers, Terry.