I am making some for the zed at the moment. They will have matching handbrake handles. Could do just the gear knob. They are just stainless steel balls. I will be doing some with engraving 1 - 6 gears and the like.
I am not sure about price yet. There are some really cheap ones on e-bay.
To be honest i have no idea what to ask for them. There are some very cheap ones online. But they look cheap i will have 8 of them for sale. I was going to say make me an offer?? You should be able to find a simple leather one no trouble.