Filling it in is easy and that particular area is going to mostly be hidden from general view. Shaving the piece down while more accurate, will be a task to be sure. Based on what I've seen so far of your efforts, I have no doubt that it is clearly within your abilities to get it right.
Sincerest congrats on your work so far! For my next build, I will refer to your work here to improve my own meager skillset!
-t















