HUP C8A front suspension shackle pins

[Malcolm Towrie]

Im involved in restoring a HUP and came across the unusual and quite clever threaded shackle pins and bushings used on the front axle. One bushing/pin was damaged so I looked for a new one, but couldn't find one, perhaps due to my crap search skills.
We have another 8 cwt HUP-type vehicle in our boneyard so I checked that out. It has what I consider to be a crude upgrade to the original design, namely a thin brass sleeve pressed into the rear spring eye, with a 3/4" bolt installed in the bushing with a nyloc nut fitted to prevent having to torque up the bolt and lock up the shackle. The upper shackle mount has a nylon bush fitted with a 5/8 or 11/16" bolt, again with a nyloc nut. There is no provision on either bolt for greasing.
Is this an accepted upgrade?
Malcolm