If yours isn't much worse than this it can be fixed
You will need super glue gel(yes super glue) and a sheet of 400 and 800 grit sandpaper, Adhesion promotor, SEM dye and clear.
Start by cleaning the whole wheel really well. I use equel parts alchohal, acetone, ammonia and water in a spray bottle. You are removing years of oil, grease and whatever you had on your hands. From here on wear plastic gloves(so you don't get more oil on it).
Spray or wipe the adhesion promotor on it.
Take the 400 and get rid of any big edges.
Open the super glue and smear a small amount on the bad spots and sand it with the 400 while its wet. The leather particles will blend with the glue.It should look like this
Let it completely dry. It may take several coats to fill in the bad spots so be patient.
When its dry and you have it all filled in you can sand it smooth, I start with 400 and switch to 800 for final sanding. Should look something like this
Clean it again lightly and let dry. Now spray the whole thing with adhesion promotor and let dry completely.
Make sure its above 70deg and spray several light coats of the SEM. Let dry and spray the clear. (satin looks better)
When completely dry a light coat of leather conditioner is all that's needed. It should look like this