Dennis provided a nice overview for repair of some shaft problems. Thanks for the information.
There is more discussion in the thread.
Get yourself a new strip key and cut off the bit that engages under the actual timing sprocket.
Lay it flat on the crank stub to ensure correct seating. Set it aside when satisfied.
Take your NEW GENUINE MB pulley and offer it to the stub .
Ask yourself is it a snug fit?
If in any doubt use Loctite 163--again a few drops, so don't go mad lathering it on the assembly process.
Place the key in the work area and secure it with Vic's favorit gob whack Quick JB weld, again clean off any excess oozing out . Tape it down
Let it dry.
Now with a file, carefully open up the keyway slot at the INNER end of your new crank pulley to create an entry ramp on three sides of the slot (about 1.8th or 3mm .
Mark the end of the crank pulley & the timing case with a paint stick and CAREFULLY offer up the pulley so that doesn't displace the keyway .
Once entered onto the stub use the old bolt and cupped washer to fully place the lot onto the crank stub , using the old bolt seat it home.
If you have used 163 immediately back out the old bolt discard, & using a new bolt and cupped washer secure to 240lbf and then 90 degrees of angle tightening to secure it.
I recommend using a new crank seal if in doubt and YOU MUST seat it square in the case (NO GUESSING) to avoid a leak VERY IMPORTANT.,
All the best
Here endeth the lesson .
Fah fah fah