[JPBrecheisen]

I can't say for sure about the relationship between the keyway and the timing mark on the damper but you could check it by doing this:

Take the No.1 plug out (removing them all will make the engine roll over by hand easier) and turn the engine over in its normal rotation until you see the intake valve for No.1 close and a bit further until the piston is at the very top of its stroke. This may take a few tries to get it perfectly at the top. A nice bright pen light should allow you to see the the piston through the spark plug hole as you do this.

With the No.1 piston at Top Dead Center/ Upper Dead Center, the mark/line on the outer portion of the damper should be aligned with "0" on your timing scale. If it is not, there may be an issue with the outer damper. If the key way is wasted you would be able to rotate it back and forth a few degrees with the belt off. If you can't "rock rotate" it back and forth on the crank nose, the key way is probably fine. The one dealt with tuned back and forth without movement of the crank.

Jonathon