Yes I have a brand new Nardi Leather "Prestige Line" Gear Knob for sale.
I bought it from HJC (the only official Nardi Importer in Australia) and have the receipt to prove it.
It's a universal kit (3 allen key type screws to fit to any shifter shaft) and comes with all you need to get it in your car (allen key, screws and instructions).
Tried it on for a day and found it not quite right for the MX-5. I want $80 my loss is your gain. I will send it out at your expense or pick-up from Maroubra (Eastern Suburbs).