Ok, I thought I had pics of this process but I can’t find them. Word salad will have to suffice. First order of business Carl is to determine if the pivot pin holes in the hinge arms are worn. They’re 5/16". If by inserting a new 5/16" bolt the fit is sloppy you will need to get them bushed, otherwise you can try reaming them out to 8 mm and go to a larger 8 mm pivot pin. While my hinge box pivot holes were sloppy as hell the ones in the pivot arms themselves were decent as is.
Next you need to replace the worn pivot holes in the hinge boxes and get them aligned with the hinge arms. For that you need to make a simple tool. It’s basically two short lengths of rod stock threaded at each end and joined together using a long coupling nut. I had a pic of it somewhere but can’t find it. It looks something like this - apologies for the lack of specific lengths:
I couldn’t locate a 5/16 x 24 coupling nut so threaded 5/16" rod stock UNF on one end and UNC on the other. You could otherwise simplify the fab by using UNC threaded rod stock and nuts but the result may not be as accurate.
To address the hinge box pivot holes I cut eight 1"x1" squares of 1/8" bar stock and then using a press precisely drilled 5/16" holes perpendicularly through each, centred about 3/8" in from one edge.
Leave the hinge boxes bolted firmly to the body but clean away any rust and paint around the pivot pin holes best you can for later welding in the repair pieces - not much room to work. Hinge arms positioned in place. You run each of those 5/16" threaded rods through the pivot holes of the two hinge boxes and their hinge arms while positioning the repair pieces, which you manipulate in place such that when the hinge arms swing out they’re as square with one another as you can get them. You snug up the nuts top and bottom, recheck your hinge actuation then tack weld the repair pieces in place. Remove the assembly and repeat on the other door.
Then you have to get the hinge boxes out to complete the welds on the repair pieces. Note that you’re not actually repairing the original pivot holes in the hinge boxes but replacing them with twice the bearing area. I used new grade 8 bolts bolts that I modified to allow lubrication while locking the pivot pin in place to prevent its rotation, this thread.