I hope your grandfather told you to e-mail Brother Jordan also. I have some ideas about how I would write such a paper, but the documentation would take me a lot of hunting to find. Pastor Jordan may be able to direct you to the written material you will need.
I was telling Brother Taylor that it would be good to start with I & II Timothy where the saints were turning from Grace back to the Law. They did not turn from Christ but they did turn from Paul. This led to the dark ages where the apostate church tried to rule in order to bring in the Kingdom and claimed to be the successors of Peter and set up a non-Jewish priesthood.
During those dark ages there were small groups who did preach and teach salvation by grace. John Huss was one of those. There were also a group who called themselves “Paulinist” because they followed the teachings of the Apostle Paul.
It is enlightening to point out that when Martin Luther brought about the Protestant reformation it all began as he was reading the book of ROMANS. There he rediscovered Justification by faith. He did not realize that the reason he discovered it in Romans is because that was the first epistle of Paul in the Bible or that Paul was given the revelation of Grace. But enlightenment began with turning back to Paul’s epistles as recorded by church history. Martin Luther thought that the book of James should not be in the Bible because he saw how it contradicted Romans 4. However, he should have read James 1:1.
The next major person in the recovery of truth was C. I. Scofield. Some have called him the father of Dispensationalism. If you have an Old Scofield Bible see his note on Ephesians 3 at the bottom of the page. You should be able to find a lot of information on him. He taught that the Church, the Body of Christ, did not replace Israel, that God will fulfill his promises to them in the future after the age of grace. Then you will want to ask Pastor Jordan what you can read about J.C. O’Hair who began to preach Pauline dispensationalism as we do today.