Looking for half brother born on or around 7/21/67 in bridgeport ct.

Hi all, I am hoping that someone can help me. I just recently found out that I have a half-brother. I know that he was born in Connecticut in July of 1967 in Bridgeport CT. The adoption agency used was Catholic Charities. My dad spoke to the woman there and she was supposed to mail a letter to him and let him know that we were looking for him, but no reply. I am sure that it is because he probably wants nothing to do with my dad or us, but I figured I would give one last try and maybe by some last chance or miracle he would read this and change his mind. I have other info, but don't want to give out to much. I know the biological moms name is Gwendolyn and my dad's is David. Please, if anyone can help--I need to know. Thanks.