Paul's first letter is generally believed by scholars to have been written in the late 60s AD and what is now called the Gospel of Mark (or parts of it) is believed to have been written before any letters by Paul and before the other "Gospels" but those are minor points. The rest of the timeline you offer seems as close as can be known at this time. And you don't claim the four gospels were written by the men whose names are attached to them which is another point in your favor.