Finally got a chance to take the switch out. It was internal, mechanical, fairly simple and easy to fix. Might last a long time now or we'll see. If you have never had one apart, there is a spring inside so pay attention lifting the circuit board cover slowly.
In this case a brass slider/shoe rides over the contacts and it had worn itself to the point of hanging up. Weird because it was very sudden and showed no sign of resistance previously. A small file to smooth/bevel out the contacts and edge of shoe and back together it went.
Have not tested the fuse part yet. Needs a long drive for that.
