A different approach?
When I bought my '86 GTV6 the leather steering wheel looked rough. It was pitted in areas and it was beginning to look purple. The stitching was still good, however. I opted to have a new steering wheel installed (forgot the name) but looked sporty in all black. The problem was the diameter being smaller. I noticed the effect of this mostly in low speed, tight turning - like in a parking lot. I had to turn the wheel too often to make sure I got the radius I wanted.
I looked back at my original steering wheel and thought that maybe I could make it look better. If it didn't work... nothing really lost. I started with wet/dry sandpaper at a 400 grit. Gently wet sanding smoothed out the pits. I wasn't very aggressive... and probably could have done a little better... but it made a great improvement in the smoothness of the surface. Next, I ordered from Tandy Leathercraft in Hartford CT, black leather dye and an applicator. I also ordered a product they sell called Fiebing's Acrylic Resolene, which is a leather finish. The dye seemed to absorb very quickly into the leather. I probably should have done a second coat... but it looked good. While the leather was still damp with the dye, I applied the Resolene. The result was a steering wheel that, at a minimum, if it had been on the car when purchased, I would have had not inclination to swap out.
Again, in my case the stitching was in tack. That gave me the opportunity to just work on the finish. The steering wheel is swapped back in, and I'm very happy with the results. Hope this helps.
Aaron