> when He made his claim to be descended from David, the Jews, who were sticklers for family records, did not dispute it
And who would have recorded that dispute if they had made it?
You are argueing that an absence of evidence is evidence for existence. In the very early years, people would have no more spent their efforts denying CHrist than skeptics of the late 1990's spent debunking the Heaven's Gaters. Simply wasn't worth the effort.
Your ignorance of the Jewish culture is also extensive. Josephus can be purchased at amazon