As Anvy said, great job after a while away.
Also watch your lower arch when you are shaping the extension edge try to file just the corners and not file the sidewalls round as you are losing the strength in them when you take out the sidewall.
All you need to do is literally file the corners with the file underneath and angled upwards, this will remove the corners and leave the sidewalls in tact, therfore leaving your lower arch in and the strength and support that you need.
Well done for posting
:hug:
Jen xx