Just the very top layer is missing and within my software parameters its set as 1.2mm so im guessing thats all thats missing. I use the software that came with my printer which is JGcreate. I took another picture last night of the unfinished nut. its just the very inner nut surface but... it still did the layer that applied the "battlebots" logo so thats what lead me to believe that the very top layer was required by fill. The size I chose was 20% of the original STL from the link below. I am 100% okay with removing the "battlebots" writing from the nut and just adding a smooth layer or whatever is easiest.

https://www.thingiverse.com/thing:3887284 20200313_230846.jpg