Good luck Captain,
I have yet to find a replacement source, and machining a worn out hinge for bushings is not a task for the faint-hearted.
Inland Andy's solution of door sag is to re-hang the door on the hinge.
If you need a replacement for a seriously damaged hinge, you will be consigned to the scrap yard.
I hope someone else posts a more optimistic response.
p.s. I have successfully implemented a solution that works for me on worn out hinges; Et al shot it down in a previous thread, so PM me if interested.