This podcast episode on Niccolo seems promising.

I've just listened to this beautiful voice of the narrator reading a letter from Niccolo, which he wrote after he was sent in excile. 

Just facinating.

https://open.spotify.com/episode/317XgzXv6or5A6sC7zElIp?si=Jiro0oayTLGOSnjQE9ZMlw