Here you can see the original pawl slots and my first and second failed attempts at cutting new slots. I got it right the third time.
On the second winch I got it right the first time. Both of these winches have worked perfectly for 4 years since the repair.
Go for it!
Don't bother filling in the old slots. You are better to just cut new slots into the winches. They don't need to be at 90 degrees to the old slots, so long as they are directly opposite to each other. Give yourself lots of space in case you screw up the first and second time. (I speak from...