Wherefore art thou, aberil?

[Jorge_Stolfi]

1. They are different:  b)Unintentional:  I) Mistakes: Ia) Scribe 2 Scribe 1

There was only one scribe.  Besides the consistent handwriting, those month names were written after the Zodiac section was completed, hence almost certainly in a single setting.  Then why would there be multiple scribes involved?

One possibility is that the owner of the manuscript at the time (the Author, his boss or patron, his client, some later owner, etc) wrote the names that he wanted for each page on a piece of paper, or in pencil on the page itself, and gave it to a scribe.  The scribe did not know the language of those names, and struggled to read the Owner's handwriting.  He did not realize that the two Aries were the same month, so each time he copied the month name with slight variations.

Maybe...

All the best, --stolfi