Door hinge help

[ReeceB]

Hi all,
Long time lurker first time poster here, I have to say this place is a great source of info for keeping these old girls on the road!

My problem is that my drivers side door opens way to easily and has little to no resistance, if I open the door on a slight slope it flys open.
My hinges were new when the truck was restored some years ago now, and the door shuts perfect and has no sag.

Is it possible to replaced the bushings circle in the pic below with out replacing the whole hinge? as I would have to paint and replace the hinge again.

Also a picture of the truck in original factory colour