This is a common problem on my truck ('84 Mazda B2000) and before I painted it, I hung the doors and tack welded the hinges to the truck, then just removed the doors from the hinges. They kept going out of adjustment no matter how much I torqued the bolts down so I had to do something permanent. So that's what I'd suggest, adjust and tack weld them. But that's assuming you have access to a welder and know how to use one. I'd be willing to bet that you could drive it to a welding shop once they were adjusted and take your doors off there, and have them weld the hinges. They'd probably put a nice smooth weld on and then you could simply spray some paint on the area to seal it back up, or just smear some 100% silicone sealent over them and put the doors back on. You could do that really cheap. Just some ideas if this is something that is likely to recur if replacing the hinges isn't regarded as a long term fix.