No text, but a visual code

[Antonio García Jiménez]

JKP, I agree with you when you write: the VM author had a working knowledge of Latin scribal conventions that suggests classical training.
   
And as you also say that doesn’t mean the text is Latin.

What I think is that the author invented a code of symbols using some glyph shapes derived from Latin, only some that fit his purpose.

I am not an expert in paleography, but it would be interesting to know if in the high Middle Ages there were loans from Arabic script, since Arabic was then the language of culture. Astrolabes were instruments developed by the Arabs and I think they can explain some things related with the VM.