I would make that with a boss feature:
http://www.youtube.com/watch?v=OFsNYV8CRzo

Using arcs to get the basic shape.

Then use the hole wizard to add the mounting holes:
http://www.youtube.com/watch?v=1EXpIpgpFEY

Then use a chamfer to add the sharp cutting edge:
http://www.youtube.com/watch?v=eyylz3ZmWFg

If you get stuck send me an email.
If you want I could send you the solidworks model of your crusher arm I made to do that stress analysis a while ago.