Considering your seat covers are hard and about junk, nothing to loose.
Can wipe them down good with lacquer thinner, will soften them up some and clean the surface for the next step vinyl spray die/flexible color.
Dupli-Color vinyl and fabric flexible finish.
A couple good coats while the seats are still soft from the lacquer thinner. Let them dry overnight before use.
Any small rips or tears you can use some clear airplane glue to help fill them in, let that dry overnight too. 3M Clear Plastic and Emblem Adhesive is the same stuff. That cleans up with lacquer thinner.
That should transform things for you in a satisfactory manner.
Then you can go have fun with your car instead of having to work on it.
All the dash pads I took out years ago I rubbed down with Vaseline and put them in the hot attic . Just got three down to sell. They are all still as soft as new. Did the same with seats.