Looking at a 68 JD 4020 that the frame rails are welded on both sides. Owner says it was that way when he bought it a couple of years ago. He doesn't know the history of tractor and whether it was a loader tractor etc. How hard is it to find serviceable side rails and how hard would it be to replace both of them? Is it a bad idea to use as is? I don't plan to use it for anything except for a backup tractor on a disk mower, rake, and square baler. Do you have to split the tractor to replace the rails? I don't really need another tractor that I would have to spend a lot of time and money on for a backup to my backup tractors. I fell in love with 4020s when I was in high school and always wanted one and it would go good with my 3020 and 630. Any suggestions would be appreciated.