Driveshaft won’t engage powerhead

[TownsendsFJR1300]

Personally, I've never seen one that isn't. Not that I've seen everything, of course, but have probably seen easily over a hundred of various manufacturers' driveshafts.

My pic (shown again below), of my driveshaft, seems pretty soft by the WP Keyway. You can see where I nicked the shaft trying to remove the key.

it was not stuck that hard, but damaged pretty easily. WAY easier than any decent SS I've machined. Perhaps just hardened more at the splines and other end??