You could try calling the local CPS or the county prosecutor's office. You could also check newspapers from that time period.Childhelp
might be able to give referrals.
I called them once and they were able to help me out. I reached a dead end but at least they were able to tell me who to call.
Sounds like you don't have a lot of info though so it may be hard to find anything out in your case. But it doesn't hurt to try. If you're unsuccessful, like you said at least you can say you tried and maybe the process of trying to find out may be cathartic. You might even be able to track down other victims.