Who is the Demosthenes at the end of Demosthenes 56, against Dionysodorus? An exercise in methodology

The common opinion is to identify the Demosthenes at 56.50 with the orator. However, this identification is extremely unlikely, especially on chronological grounds. This article attempts to narrow down the identification by proposing another Demosthenes, and in the process points out the methodological danger of identifying a homonym with the famous bearer of the name.