Ahh what a sad story...your mum must know his surname! Is it not on your birth certificate, have you ever seen your birth certificate? Its hard without knowing the surname, but if you do ever find it out, and I sincerely hope you do, you could try 192.com, or findmypast.com, friends reunited...will try and think of some more for you, just thought of something else..do you know what area he comes from, you could advertise in the local papers...whatever happends, best of luck xxx