D M Murdock (aka "Acharya S") has been a controversial figure in the discussion of the historicity of Jesus. Her earlier writings were heavily criticized for use of Egyptian, and other ancient culture, artifacts liberally to support the complete fabrication of the Jesus story. Below is an excerpt from a fairly recent DVD entitled "Great Minds of Our Time: D.M. Murdock". This blogger will leave it up to the viewer to decide how credible she is presently.
Bottom line in this discussion: It makes no difference whether or not Jesus is based on a real person. The character is effectively fictional.