Is the Hadith: "Joseph is more beautiful than me in form, and I am more beautiful than him in character" authentic?

The aforementioned hadith in the question is still a manuscript in the Tafsir of Najm al-Din al-Nasafi and is not authentically attributed (musnad). It appears to bear signs of fabrication. Al-Bara' ibn 'Azib mentioned that the Prophet Muhammad, peace and blessings be upon him, was the most beautiful of people in countenance and creation. In Sahih Muslim, it is stated that Yusuf (Joseph), peace be upon him, was given half of all beauty. Scholars have differed regarding the preeminence in beauty between the Prophet Muhammad and Yusuf, peace be upon them both. Some held that Yusuf was favored with half of all beauty over everyone except the Prophet, peace and blessings be upon him. Others said that Yusuf's favoritism applies to everyone except the Prophet Muhammad, peace and blessings be upon him, and that the Prophet attained the ultimate degree of beauty.