I would do, (or have done), a quick, but hot spot weld of the crankpin to crank web on the side opposite the crank web from the rod. Then grind the spot weld down if necessary for clearance between the front of the crank and the crankcase. (I am assuming the crankpin hole goes all the way through the crank.) I've welded cranks numerous times before and never had a problem, with the engines running in use for years and at high rpms. It needs to be done quickly, and with Mig or Tig; not a torch.
AV8TOR