Coguaro, X3 etc swing arm

[3potjohn]

On the Coguaro the swing arm spindle consists of a long bolt which pushes through and then a nut with two washers is tightened,to an unknown torque, to secure it.
On a couple of occasions I have found some side to side play. This proved to be due to the nut coming loose. However I can’t think that this isn’t due to some wear. The bushes have no grease nipples and I do not know if they are metallic or plastic.
Doug has a pair of bronze ones left said to be correct.
My favoured option should it prove necessary would be plastic , Igllidur being suggested as a candidate material.
Anyone able to illuminate me?

['It must be a .....']

The frame is threaded so that you can adjust the end float and the nut is for locking it all up.
The centre section that isn't in the plastic bushes can rust and make it difficult to move/remove the spindle bolt/swinging arm.

As your nut keeps coming loose the bushes may be seized and turning the spindle in the frame thread?