Bucket seat track/rails

I'm not aware of replacement repair parts for the tracks. Maybe someone else will post that knows differently.

The only way I know of - is to get good used replacement track assemblies. I do not think bench seat tracks will work. On a bench seat there are two tracks, on buckets there are two per seat, plus the mounting location on the floor is quite different, on the bench they mount to a raised portion of the floor - the tracks are shorter in height.

You might be able to substitute the outer tracks with bench seat units, if you shim the bottoms of them to the same height and rig some sort of way to bolt them down.

Where I would look: ebay, moparts swap meet section, this websites for sale section, junkyards, etc. You'll find a set - it'll just take some time.