Which things in the manuscript can be dated?

[MarcoP]

There aren't many entries in the MS that can be called 'later' with any confidence.
I think these few cases are:

- the quire marks. logically, these would only be added after the MS was completed and ready for binding.
- the month names in the zodiac area.
- the folio numbers
- much more recent annotations that seem to be in pencil: 'a' 'b' and 'c' above some of the cosmological pages
- the cover and anything written on it

I think that many of these could be dated, with greater or lesser confidence.
The script and spelling of the month names look like particularly good candidates.