Coffee Appreciation

This "project" is now in its second year, but I've liberated my parents' old Spong cast iron grinder. Mum enjoyed coffee but passed away many years ago, and dad rarely drinks it.

Last Christmas I dismantled it, washed all the dust and blu-tack out of it (courtesy of my sister dicking about with it as a kid), and left it at my dad's in pieces.

As you can see, one of the tabs to bolt it to a wall has sheared clean off, possibly the result of a drop. I have two questions:

1. Any bright ideas for repairing the snapped-off piece? Apparently welding cast iron is tricky, so maybe just glue?
   
2. Does anyone know how I can stop the light bloom of surface rust in some areas? It's most noticeable in the areas that don't have a black finish. Is there some product I should be using to treat the exposed iron surface like linseed oil?