http://tools.ietf.org/html/rfc6598 uTorrent doesn't use the ip address range to define a peer as local. It uses the ability to communicate on the local peer multicast channel to do that.
Even with all the information included in the .torrent, you're still effectively trying to bruteforce SHA-1, which is EXTREMELY impractical from a processing speed perspective. EVEN WITH gpu processing, you're still looking at machine DECADES to win the race.