Can I find out where my trust fund was held when my mother has never and will never tell me a) how much money was in the account and b) which bank or trust the money was kept. This money has been "gone" since late 1970's. To this day, she insists that a stepfather took it, but that can't be true without her consent. This indicates to me that she benefitted somehow and does not want me to get the money. Also, my real father, who set the fund up to start with, died in 1978--thus, the one who could have asked why I didn't get the money was "conveniently" out of the way...

Unfortunately, it doesn't sound like you have any evidence that an actual trust fund was ever set up for you. Odds are it was money that your father intended for you that was never actually put into a trust fund. It is not unusual for people to talk about "trust funds" and "college funds" for their children but never actually segregate the funds.

The best I can suggest is to check on unclaimed property for each state (if more than one) that your father lived in from when you were born until 1978 under both your father's name and social security number and yours (separate queries). This is a long shot, but worth the limited effort that it will take.