Measure the diameter of the steering wheel then get a generic cover for that diameter wheel .
Go to a hard wear shop and get some foam pipe insulation , slit it lengthways then push it over the wheel & secure with plant ties.
Go to a sports store and get some tennis racquet or golf club grip tape & wrap the wheel with that
Find a dissability support store / assisted living store and see what they have that could be used.
If you have bad arthritis you will find a host of things there to make your life a lot less painful from cuttelry slip ons to can openers to key extenders.
It can be a life changing experience.
It took me 3 years to drag dad down to one but once he was there he would not leave, bought box loads of stuff that made a big difference to his life
The long off set back scrubber was his most favourite item and he had a left & right hand pair eventually. After that the yard tap handle covers meant he could turn the taps on & off again.