Loose balancer damaged the crank - RD28

Hey Guys,

Went for a drive at the start of this month and after about 15 minutes the dash lit up, lost power steering, and water temp shot up. Quickly pulled over and had to get towed home.
I got the Balancer off and found the woodruff key and the keyway had been destroid. The key for the timing gear was ok. (Pictures attached)
Aparently this is somewhat common with the RD28.
I think this was all caused by the fact that the crank bolt didn't have locktight on it and so it came loose.
The balancer, timing gear and washer were all damaged so I'll be replacing those.

The plan at this time is to have the damage filled in with some weld and then shape a new keyway. Maybe also grind the keyway to the end of the crank for more support and use some square dowel as the key.

But before I make the investment and go ahead I wanted to hear from others that have had or seen this issue before.

Has anybody come across this before?
How did you go about fixing it?

Any recommendations or opinions would be appreciated.

Thanks in advance.

If it was mine, I would pull the engine out and fit a new crank. That being said, there are specialists that spray weld cranks and shafts. This is method reduces the heat used for the repair.