Gearknob badge

On my '83 Campaign, I have the golfball gearknob, unfortunately there is a crack on the R-1-2-3-4-5 badge in the middle.

Does anyone know if it is possible to buy these individually,,it is annoying me perhaps more than it should, a replacement centre may well be cheaper than a replacement gearknob at current ebay prices..cheers

Still haven't found one..any ideas gratefully received.