Morten St George Theory

[Linda]

However, some culture creeps in, and it helps give us clues.

This is a crucial part to understand. I am absolutely convinced that if you were to present Virgo, Gemini and Sagittarius to a curator with the relevant expertise, they would date it to 1400-1430, give or take a decade. 

It's still possible to say the MS was made later. But this would already require two violations of Occam's razor. You'd have to add the condition that old vellum was used, and that old fashion was used, which happens to overlap with the period of the vellum in the first place.

Koen, I accept your research on this completely, and agree with your conclusions. The fashion info you found means that even if Morten had found 200 year older fashion, that he would still have to explain that which you have found matching 15th century examples.

Morten, i apologize for misspelling your name earlier, i fixed my note but the mistake remains in quotes.

I am wondering why you insist the manuscript should be created in the 13th century, i thought you had said it would be a copy of an earlier writing. My take is that it is not a copy of anything in particular but does seem to reference other related texts, generally scientific ones though, herbals, maps, astronomy, that sort of thing, not like your 15th century example posting, which are more tradition based.