Muhammad bin Sirin said: "I asked Ubaida As-Salmani about the Ayah: (to draw their Jalabib over their bodies.) and how the jalbaab was to be worn, he demonstrated it to me by pulling a sheet of cloth over his head to cover his entire body, leaving the left eye uncovered." [Tafsir Ibn Kathir (Part 22): Al-Azhab 31 to Yasin 27]
That's not the source to the hadith, but to a tafsir. While Ibn Kathir is a widely respected imam, he is the student of Ibn Taymiyyah, this may cause sunni imams that are not wahhabi/salafi say that this source can not be trusted.
The only sahih hadith I've found where it talks about covering the face are these:
Narrated 'Aisha: [...] While I was sitting in my resting place, I was overwhelmed by sleep and slept. Safwan bin Al-Muattal As-Sulami Adh-Dhakwani was behind the army. When he reached my place in the morning, he saw the figure of a sleeping person and he recognized me on seeing me as he had seen me before the order of compulsory veiling (was prescribed). So I woke up when he recited Istirja' (i.e. "Inna lillahi wa inna llaihi raji'un") as soon as he recognized me. I veiled my face with my head cover at once, and by Allah, we did not speak a single word, and I did not hear him saying any word besides his Istirja'. He dismounted from his camel and made it kneel down, putting his leg on its front legs and then I got up and rode on it. [...]
Sahih Bukhari 5:59:462
Narrated Safiya bint Shaiba: 'Aisha used to say: "When (the Verse): "They should draw their veils over their necks and bosoms," was revealed, (the ladies) cut their waist sheets at the edges and covered their faces with the cut pieces."
Sahih Bukhari 6:60:282
But even these hadith are vague. They do not literally say that you MUST cover your face, which is the reason to different fatwas/interpretations.
The sunni tafsir of Ömer Nasuhi Bilmen that I have says that the face doesn't have to be covered. Other sunni tafsirs I've found say something similar. One of them refers to the hadith that is mursal you mentioned, which means that the sahaba saying the hadith is not mentioned. According to the imams of the tabiin and taba-i tabiin, this doesn't mean that this hadith should be thrown away, if another hadith refering to that subject is not found, than a mursal or weak hadith may be taken.
Conclusion: this mess called Islam is harder to understand than you think.Note: I may be wrong according to the sunni creed, don't get mad at me if I am.
Topic: No hijab in Islam