En 1346 se comienza un cimborrio mudéjar para dar luz a la cabecera.... How should cabecera be translated? Ceiling?
En la Seo residirían 6 dignidades y 15 canónigos.... Dignidad seems to refer to some kind of honorary officeholder or recipient of a stipend. I've used the somewhat arcane 'prebendary' for now.
...añadiendo dos tramos completos a los pies. Which part of the cathedral does pies refer to?
...adornados con el llamado ajedrezado jaqués en el exterior... What is ajedrezado jaqués?
...con ventanucos entre capiteles historiados..historiado can mean 'containing a history' or 'the subject of a history'. I'm voting for the former, to be translated as 'inscribed'. Comments?
..nueve ejecutados, en persona... Hmm, "executed, in person"? What does en persona signify?