This week I sanded the inside of the ribs and top plate linings and cleaned up the F-holes. The sanding wasn't really necessary, and probably only served to smooth out any lumps in the hide glue squeeze-out. However, the F-holes needed the cleanup.
I used a very narrow strip of sandpaper to remove the knife marks from the straighter sections of the F-holes. For the highly curved and round areas I used a small machinist's round file. Once that was done, I sanded the outside again to remove the remaining pencil marks.
While checking the remaining lining material, I realised that there wasn't enough to line the entire bottom perimeter. Fortunately I had cut some extra strips of willow. So, back to the Luthier's Friend and after about 20 minutes I had more than I need for this instrument.