1930 ish guitar ends up needing a nut slot raised.

I was finishing up on the 1930s supertone when I noticed, with a decent strum of the low E, the guitar buzzes. I didnt notice before because I finger pick this guitar kinda lightly. It's as I thought. The slots in the nut is too low. I knew this while I was working on it. The measurements were very low. But the guitar played fine. Well all the strings do except the Low E with a strong strum. I will raise the slot. It is a wood nut and I am trying to keep as much as I can original. I will need to use rosewood or ebony fine dust and super glue and then re-file the slot to the proper depth.

Picture of nut:

https://www.dropbox.com/s/to6fwmt7px0t5lg/20200804_171346.jpg?dl=0