Sounds like your only issue now is the dead-spots?

If that's the case, take both senders out and measure the resistance as you move the arm. The resistance should increase/decrease at a fairly constant rate. As was stated, you'll probably seen a "jump" at a certain point in the travel. Look closely to see if there are any irregularities in the windings/arm at this point.

Maybe your adjustment/bending the arm caused intermittent contact at certain points during its travel.