Hi steveduf (and others).  Another nice find.

Fortunately, the missing mother of pearl inlay should be relatively easy to duplicate given the circular shape.  I would use the Scotch (tm) painter's tape and super glue trick to hold the mother of pearl on a flat head bolt, insert in an electric drill, and file/sand paper away excess material (be sure to use a face mask, since you don't want to breath in the mother of pearl).  I would attempt to add the veins (perhaps using black super glue and polish surface with tooth paste to match existing).

You would be losing a lot of sound (at least on the open notes) if the grooves in the nut are not removed.  You should be able to file the nut down as needed.

Who ever used the violin played with a lot of dirt under the finger nails.  A luthier would use a hand plane to obtain a new curved surface on the finger board.  I would try to use curved surface sanding block since I would not trust myself with a hand plane for this.

I would use some type of perlon violin string since you obviously want to retain the pegs.  And please replace the tail piece gut since I would not trust the holding power of the original.