Those dowels are far too tight of a press fit to get a weld to hold. Last resort method- - - -remove the crankshaft and use an electron discharge mill (EDM) to burn the dowels out. Buying another crankshaft would be less expensive, since it's the same as a 235 crank. A solid carbide drill bit in a very accurate drill press would be another option, which would also require removing the crankshaft.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!