Partially restoring a beat up horn pad.
You can use paintable acrylic caulk to fill any cracks. Caulk shrinks when it dries, so apply multiple coats if you want the completely fill the problem areas. I only applied two coats in a few hours, and it could clearly use one more coat.
Apply liberally, spread around. Work into the cracks, then wipe the excess. Do not use silicone caulk. It isn’t paintable or stainable, and doesn’t really stick to rubber.
I use kiwi shoe dye to darken leather, be it seats, shoes, or steering wheels. I wouldn’t apply the dye to a wheel with nice original patina, but it works great for your e28 wheels, or even factory CS wheels that are beat up, but have no saveable patina. Don’t use it on white stitching. That is a steering wheel collector’s pet peeve.
The dye shouldn’t really work on rubber but it can help. You need to let it air dry on the surface. It doesn’t soak in like you see on leather. Vinyl paint is another good, if not better option.
It could be better. I wasn’t trying to fully restore the button. I just wanted to document the process before the wheel changed hands.