Dear Kallistos,
It seems to me, you offer very interesting theme.
It woud be rather interesting to me to find out anything about influence rendered by Ptolemy on development of Hellenistic architecture. Whether someone can tell something about it? Whether there is special article or monography?

I can name one book where the role of Ptolemy Lagos is described very colourfully, since he is one of the main heroes. It is the novel by Russian scientist and paleontologist Ivan Efremov "The Tais from Athenes".
I do not know, whether the book is issued in English, but I think, what yes, as Ivan Efremov is considered in Russia as one of the best SF writers of XX century.

With best wishes - architect Mnesikles