M born on 7/6/1970 in or near Boston MA

Hi, I'm searching for a half brother born in Boston in 1970 , I understand his mother maruja was from chile but not sure if she kept the baby or put him for adoption . My father is from Cuba and was married at that time to my mother estela . I was born in 1971 and my brother in 1969 both from boston and we've been trying to find our half brother, I saw your post and thought it wouldn't hurt to reply just in case.