woodruff key (A833)

ChargerST said
Interestingly the slot in the old pin is the same width..

Same width as what?
Same as the new pin,or
same as the fat-boy woodruff.

ChargerST said
Do I have the wrong key or how is this supposed to work?

Yes wrong key;
The skinny half-moon key that fits in the skinny slot, is not technically a woodruff key.