I was anonymous in my past, how do I get credit today?

As a youth I was fortunate to meet many writers and producers. Early on I never took it serious (being 8 when discussing Jaws while it was in production). Later, as a teen, I still took nothing serious, but also used drugs, thus wanting to keep my private life private, I refused credit and asked for any money I earned to go directly to charity.
Now, decades later and long since clean, I want to try and get some of those credits established. It is nearly impossible as many of those I dealt with are now dead, or scared it is a money grab. Obviously any verbal agreement made as a minor is technically unenforceable, but with the exception of James Cameron (on Titanic) and Barry Levinson (on jimmy Hollywood) no one owes me any money and I state that publicly.
I only have one producer that will confirm a consulting credit, Greg Strangis for War of the Worlds The Series. We both submitted the credit to IMDb years ago and it never got accepted.
Once I start getting some credits from the 80's it will improve my ability to get more.