[Jacques Reed]

Bruce,

It swivels and is hinged. A castle nut and cotter pin under the floorboard keeps the nut from loosening as does the one at the hinge.
A real pain to get to the cotter pin under the floorboard to remove the nut!

Freed up this one too by gentle taps left and right after drowning the stud in Penetrene. I then put a Vice Grip on nut and worked handle back and forth a small amount until cotter pin sheared from fatigue. I was then able to remove castle nut and handle from floorboard.

Cheers,