I did the mod as my pulley was wobbling .The crankshaft end was all chattered. I ordered a crank milling tool from germany which took a few thou off the damaged crank and left it as new , great job!!!.
I ordered a new pulley and had the old pulley and new pulley drilled with two 3.8mm holes one either side of the bolt hole. The new pulley was then drilled to 4.0mm .I bolted up the old pulley and used it as a guide with a 3.8mm bit i drilled into the crank .
I then drilled with a cordless very slowly with a 4mm bit into crank marking depth with tape on drill bit.
Then i put two steel dowels into the crankshaft with strong stud lock . Then the new pulley and a new bolt torqued with some blue threadlock.
Its as new 50k done since.